Magnifying observation apparatus

ABSTRACT

Work to obtain an optical and an electron microscope images at an identical display size is facilitated. A magnifying observation apparatus includes: an electron beam imaging device that obtains an electron microscope image in a chamber; an optical imaging device that obtains an optical image in the chamber; a moving device that moves the both devices such that an optical axis direction of one of the both devices is aligned with an optical axis direction of the other device; a display section that displays the electron microscope and the optical images; and a magnifying power conversion section that recognizes a magnifying power of an image obtained by one of the imaging devices and converts the magnifying power, which is used to obtain an image having a display size substantially identical to that of the image, by the other device into a magnifying power on a basis of the other device.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims foreign priority based on Japanese PatentApplication No. 2010-152536, filed Jul. 2, 2010, the contents of whichis incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a magnifying observation apparatus inwhich an optical imaging device that can obtain an optical image with anoptical observation device such as an optical microscope is added to anelectron microscope such as a Scanning Electron Microscope (SEM).

2. Description of Related Art

For example, a transmission electron microscope and a scanning electronmicroscope are well known as a charged particle beam apparatus in whicha signal obtained by irradiating an observation target specimen with acharged particle beam is detected to obtain an observation image. In theelectron microscope, for example, an electron traveling direction isfreely deflected and an image formation system as in an opticalmicroscope is designed in an electro-optical manner. Examples of theelectron microscope includes a transmission electron microscope thatforms an image of electrons transmitted through a specimen or a sampleusing an electron lens, a reflection electron microscope that forms animage of electrons reflected from a specimen surface, a scanningelectron microscope in which the specimen surface is scanned with afocused electron beam to form an image using secondary electrons fromeach scanning point, and a surface emission type electron microscope(field ion microscope) that forms an image of electrons emitted from thespecimen by heating or ion irradiation (for example, see JapaneseUnexamined Patent Publication No. 9-97585).

In the Scanning Electron Microscope (SEM), which is one example of theelectron microscope, secondary electrons and reflection electronsgenerated in irradiating the observation target specimen with a thinelectron beam (electron probe) are taken out using detectors such as asecondary electron detector and a reflection electron detector and aredisplayed on a display screen such as a CRT and an LCD, and a surfacemode of the specimen is mainly observed. On the other hand, in theTransmission Electron Microscope (TEM), the electron beam is transmittedthrough the thin-film specimen, the electrons scattered and diffractedby atoms in the specimen at this time are obtained as an electrondiffraction pattern or a transmission electron microscope image, and aninternal structure of a substance can mainly be observed.

When a solid-state specimen is irradiated with the electron beam, theelectrons are transmitted through the solid-state specimen by electronenergy. At this time, elastic collision, elastic scattering, andinelastic scattering associated with energy loss are generated byinteraction between electrons and atomic nuclei constituting thespecimen. In-shell electrons of a specimen element or X-rays are excitedby the inelastic scattering, and the secondary electrons are emitted tolose the energy corresponding to the inelastic scattering. An emissionamount of secondary electron depends on a collision angle. On the otherhand, an emission amount of reflection electrons that are scatteredbackward by the elastic scattering and emitted again from the specimenis unique to the atomic number. In the SEM, the secondary electrons andthe reflection electrons are utilized. In the SEM, the specimen isirradiated with the electrons, and the emitted secondary electrons orreflection electrons are detected to form the observation image. AScanning Transmission Electron Microscope (STEM) in which the detectorreceives light transmitted through the specimen is also well known asone type of the scanning electron microscope.

Although the electron microscopes such as the SEM, the TEM, and the STEMare effectively used in the observation at a high magnifying power, theelectron microscopes do not well display at a low magnifying power.Generally, the electron microscope can perform the display of tensthousands times to hundreds thousands times or millions times at themaximum magnifying power. On the other hand, the electron microscope canperform the display of several times to tens times at the minimummagnifying power. For example, in the SEM, the observation can generallybe performed at the minimum magnifying power of about 5 times to about50 times. In the observation with the electron microscope, because thedisplay is performed at the high magnifying power from the beginning, anobservation visual field becomes extremely narrow range. Therefore, itis difficult to perform visual field search that is work to finally finda site to be observed on the specimen. Preferably, the visual fieldsearch is gradually performed from the wide visual field state, namely,the state in which the specimen is displayed at the low magnifying powerto the state in which the visual field is narrowed at the highmagnifying power.

In order to facilitate the visual field search of such an electronmicroscope, there is known a method of utilizing an optical microscopein which visible wavelength light or infrared wavelength light is usedand an optical observation apparatus (optical imaging device) (forexample, see Japanese Unexamined Patent Publication No. 9-97585). In theobservation with the optical imaging device, the display can generallybe performed at a low magnifying power of the same size or less. Afterthe specimen is observed at the low magnifying power with the opticalimaging device to roughly perform the visual field search, observationis performed with the electron microscope. In order to realize this, theelectron microscope is used in conjunction with the observation opticalsystem in which the display can be performed at the lower magnifyingpower. The visual field search is performed based on the displayperformed at the low magnifying power with the observation opticalsystem of a CMOS camera or the like. Then, the observation is performedat the high magnifying power while the observation optical system isswitched to the electron beam imaging device of the SEM or the like.

In the conventional electron microscope including the optical imagingdevice, the observation is performed while the optical image and theelectron microscope image that are obtained by the imaging devices arecontrasted with each other. At this time, for the magnifying power ofthe image, the image of the specimen placed on a specimen stage isdesirably obtained in the same visual field at the same magnifying powerby each imaging device such that the sizes of the specimens displayed inthe optical image and the electron microscope image become identical.

However, because the electron microscope and the optical microscope aredesigned by different concepts with respect to magnifying powers,unfortunately the sizes of the display images differ from each othereven if the magnifying powers have the same numerical value. In otherwords, since the magnifying power is based on the size of the finallyoutputted image, the electron microscope photograph conventionallybecomes a basis in the electron microscope, whereas the monitor sizebecomes a basis in the optical microscope because the optical image isdisplayed on a monitor screen. The size also depends on a CRT monitor oran LCD monitor.

Because the electron microscope image differs from the optical image inthe magnifying power computing method, the sizes of the actuallyoutputted images differ from each other even if the magnifying powershave the same numerical value. The different image sizes are notsuitable for the comparative observation, so the images are desirablydisplayed at the same size. Therefore, for example, it is necessarythat, after the magnifying power of the optical image is converted intothe magnifying power of the electron microscope image, the electron beamimaging device be adjusted to the converted magnifying power to obtainthe electron microscope image. As a result, when an operator who is auser tries to obtain the optical image and the electron microscope imageof the same size, the user needs to understand the difference of amagnifying power determining method in each observation device, and ithas been difficult for the user to easily set the magnifying powers ofthe observation devices.

SUMMARY OF THE INVENTION

The present invention has been made in view of solving the aboveconventional problems, and an object thereof is to provide a magnifyingobservation apparatus that can easily obtain an optical image and anelectron microscope image at the same display size.

In order to achieve the above object, according to one embodiment of theinvention, a magnifying observation apparatus may include: a pluralityof observation devices; a specimen chamber whose internal space isdecompressed; an electron beam imaging device as a first observationdevice for obtaining an electron microscope image in the specimenchamber; an electron microscope magnifying power adjusting section thatadjusts an electron microscope magnifying power of the electronmicroscope image obtained by the electron beam imaging device; anoptical imaging device as a second observation device for obtaining anoptical image in the specimen chamber; an optical magnifying poweradjusting section that adjusts an optical magnifying power, the opticalmagnifying power being a magnifying power of the optical image obtainedby the optical imaging device, the optical magnifying power beingdetermined on a basis different from that of the electron microscopemagnifying power; a moving device that moves each of the observationdevices such that an optical axis direction of one of the observationdevices is substantially aligned with an optical axis direction of theother observation device; a display section that displays the electronmicroscope image obtained by the electron beam imaging device and theoptical image obtained by the optical imaging device while switchingbetween the electron microscope image and the optical image, orsimultaneously displays the electron microscope image and the opticalimage; and a magnifying power conversion section that recognizes themagnifying power of an image obtained by one of the electron beamimaging device and the optical imaging device and converts themagnifying power, which is used to obtain an image having a display sizesubstantially identical to that of the image, by the other observationdevice into a magnifying power on a basis of the other observationdevice. With this configuration, the magnifying power display ofdifferent observation devices can be unified to improve convenience whenthe user performs magnifying power adjusting work.

According to another embodiment of the invention, in the magnifyingobservation apparatus, a converted magnifying power in which themagnifying power of the image obtained by one of the observation devicesand displayed on the display section is converted into the magnifyingpower of the other observation device by the magnifying power conversionsection may be displayed on the display section, or a magnifying powerthat is set close to the converted magnifying power may be displayed onthe display section when the converted magnifying power is not set bythe other observation device. With this configuration, during thecomparative observation of the same specimen with the plurality ofobservation devices, when the image having the same display size as theimage obtained by one of the observation devices is obtained by theother observation device, the user only needs to set the magnifyingpower to the magnifying power displayed on the display section.Therefore, the magnifying power converting work corresponding to thetype of the observation device can be eliminated to conveniently use themagnifying observation apparatus.

According to still another embodiment of the invention, in themagnifying observation apparatus, the converted magnifying power inwhich the magnifying power of the image obtained by one of theobservation devices is converted into the magnifying power of the otherobservation device by the magnifying power conversion section mayautomatically be set by the magnifying power adjusting section of theother observation device, or a magnifying power that is set close to theconverted magnifying power may automatically be set by the magnifyingpower adjusting section of the other observation device when theconverted magnifying power is not set by the other observation device.With this configuration, during the comparative observation of the samespecimen with the plurality of observation devices, when the imagehaving the same display size as the image obtained by one of theobservation devices is obtained by the other observation device, theuser can automatically set the magnifying power while being notconscious of the magnifying power conversion corresponding to the typeof the observation device.

According to still another embodiment of the invention, in themagnifying observation apparatus, an electron microscope magnifyingpower range of the electron microscope image obtained by the electronbeam imaging device, the electron microscope magnifying power rangebeing adjusted by the electron microscope magnifying power adjustingsection, and an optical magnifying power range of the optical imageobtained by the optical imaging device, the optical magnifying powerrange being adjusted by the optical magnifying power adjusting sectionmay at least partly overlap each other in the converted magnifying powerconverted by the magnifying power conversion section. With thisconfiguration, the electron microscope image and the optical image canbe obtained at the same size to advantageously perform the comparativeobservation.

According to still another embodiment of the invention, the magnifyingobservation apparatus may further include an image synthesizing sectionthat synthesizes the electron microscope image obtained by the electronbeam imaging device and the optical image obtained by the opticalimaging device. With this configuration, color information on theoptical image is advantageously added to the electron microscope imageto obtain the colorized, high-resolution image.

According to still another embodiment of the invention, in themagnifying observation apparatus, the optical imaging device mayinclude: a zoom mechanism that magnifies the optical image; and amagnifying power recognizing section that recognizes a magnifying powermagnified by the zoom mechanism, and the electron microscope magnifyingpower adjusting section may include: a parameter setting section thatsets a parameter relating to the magnifying power of the electronmicroscope image obtained by the electron beam imaging device; and anelectron microscope magnifying power computing section that recognizesthe parameter set by the parameter setting section and computes theelectron microscope magnifying power obtained by the parameter. Withthis configuration, the magnifying power set by each imaging device cancorrectly be sensed.

According to still another embodiment of the invention, in themagnifying observation apparatus, the display section may simultaneouslydisplay the electron microscope image and the optical image at anidentical magnifying power in terms of the converted magnifying power onthe basis of one of the magnifying powers. With this configuration, theelectron microscope image and the optical image can simultaneously bedisplayed at the same display size, and the magnifying observationapparatus can suitably be used in the comparative observation.

According to still another embodiment of the invention, in themagnifying observation apparatus, a comparative mode and a syntheticmode may be selected as an observation mode, comparative observation ofthe electron microscope image and the optical image being performed inthe comparative mode, a synthetic image in which the electron microscopeimage and the optical image are synthesized being displayed in thesynthetic mode. With this configuration, in the comparative observationin which the images having the same display size are compared or asynthetic mode in which the images are synthesized to obtain a syntheticimage, the image can be advantageously displayed at the unifiedmagnifying power irrespective of the observation device to be used.

According to still another embodiment of the invention, the magnifyingobservation apparatus may further include a magnifying power rangedisplay section that one-dimensionally displays the electron microscopemagnifying power range and the optical magnifying power range on thedisplay section while converting the electron microscope magnifyingpower range and the optical magnifying power range into a magnifyingpower on an identical basis, the electron microscope magnifying powerrange being obtained by the electron beam imaging device, the opticalmagnifying power range being obtained by the optical imaging device.

According to still another embodiment of the invention, in themagnifying observation apparatus, the magnifying power conversionsection may output as the converted magnifying power a magnifying powerclosest to the converted magnifying power in the magnifying powers thatare set by the other observation device, when the converted magnifyingpower that is used to obtain the image having the display sizesubstantially identical to that of the image, which is obtained by oneof the electron beam imaging device and the optical imaging device, bythe other observation device is a magnifying power that is not set bythe other observation device.

According to still another embodiment of the invention, in themagnifying observation apparatus, the moving device may be a rotatingdevice that rotates the electron beam imaging device and the opticalimaging device along a cylindrical shaped outer surface of the bodyportion such that a distance to a common rotation axis is kept constantwhile optical axes of the electron beam imaging device and the opticalimaging device are maintained in a posture oriented toward the commonrotation axis. With this configuration, during the tilt observation, theobservation device side is tilted while the specimen stage side ismaintained in the horizontal posture. Therefore, the observation imagecan easily be obtained in the same visual field at the same angle whilethe optical axes of the observation devices are aligned with each other.

According to still another embodiment of the invention, in themagnifying observation apparatus, the specimen stage may include ahorizontal surface moving mechanism that moves the specimen stage in ahorizontal plane while the specimen stage is maintained in a non-tiltedstate in a horizontal posture and a height adjusting mechanism thatadjusts the height of the specimen stage.

According to still another embodiment of the invention, in themagnifying observation apparatus, a rotation axis of the rotating devicemay be included in a height variable range that is adjusted by theheight adjusting mechanism. With this configuration, specimenobservation positions of the observation devices can be the same to aheight of the rotation axis, and a working distance from the observationdevice to the observation position can be kept constant irrespective ofthe position of the observation device. Therefore, once the focal pointis adjusted, the focused state can advantageously be maintainedirrespective of the tilt angle.

According to still another embodiment of the invention, in themagnifying observation apparatus, the magnifying power may be defined bya value in which an identical display range is divided by theobservation visual field range. With this configuration, in eachobservation device, the magnifying power is defined such that the sameobservation visual field range has the same magnifying power, so thatthe user can compare the different observation images based on theunified magnifying power.

According to still another embodiment of the invention, in themagnifying observation apparatus, the optical imaging device may includean optical magnifying power reading section that reads the setmagnifying power. With this configuration, the magnifying observationapparatus side can recognize the optical zoom lens magnifying powermanually set by the user, and the pieces of processing such as themagnifying power conversion can smoothly be performed.

According to still another embodiment of the invention, in themagnifying observation apparatus, the optical magnifying power readingsection may read the magnifying power of the optical image, themagnifying power conversion section may convert the magnifying power ofthe electron microscope image corresponding to the read opticalmagnifying power, and the display section may display the electronmicroscope image of the converted magnifying power. With thisconfiguration, the electron microscope image having the magnifying powercorresponding to the optical image can automatically be obtained or theobtained electron microscope image is enlarged and reduced, and theimage can automatically be displayed on the display section. Therefore,the user can confirm the images having the same magnifying power as theoptical image and the electron microscope image to facilitate thecomparative observation.

According to still another embodiment of the invention, in themagnifying observation apparatus, the converted magnifying powerconverted by the magnifying power conversion section may be switchedbetween a state in which the converted magnifying power is displayed onthe display section and a state in which the converted magnifying poweris not displayed. With this configuration, the display and thenon-display of the converted magnifying power can be switched accordingto the application and purpose of the observation to enhance a degree offreedom of the observation.

According to still another embodiment of the invention, a magnifyingobservation apparatus may include: a plurality of observation devices; aspecimen chamber whose internal space can be decompressed; a firstspecimen stage on which a first specimen of an observation target isplaced; an electron beam imaging device as a first observation devicefor obtaining an electron microscope image in the specimen chamber; anelectron microscope magnifying power adjusting section that adjusts anelectron microscope magnifying power of the electron microscope imageobtained by the electron beam imaging device; a second specimen stage onwhich a second specimen of an observation target is placed; an opticalimaging device as a second observation device for obtaining an opticalimage of the second specimen; an optical magnifying power adjustingsection that adjusts an optical magnifying power, the optical magnifyingpower being a magnifying power of the optical image obtained by theoptical imaging device, the optical magnifying power being determined ona basis different from that of the electron microscope magnifying power;a display section that displays the electron microscope image of thefirst specimen obtained by the electron beam imaging device and theoptical image of the second specimen obtained by the optical imagingdevice while switching between the electron microscope image and theoptical image, or simultaneously displays the electron microscope imageand the optical image; and a magnifying power conversion section thatrecognizes a magnifying power of an image obtained by one of theelectron beam imaging device and the optical imaging device and convertsthe magnifying power, which is used to obtain an image having amagnifying power substantially identical to that of the image, by theother observation device into a magnifying power on a basis of the otherobservation device. With this configuration, in the observation in whichtwo specimen images are obtained at the same size to compare the twospecimen images, the magnifying power display of the differentobservation devices can be unified, and the convenience can be improvedwhen the user performs the magnifying power adjusting work.

According to still another embodiment of the invention, in themagnifying observation apparatus, a controller that controls theelectron beam imaging device may also control the optical imagingdevice. With this configuration, the electron beam imaging device andthe optical imaging device are advantageously connected to onecontroller, and the magnifying powers on an originally different basiscan be unified to conveniently perform the control.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating an outline of a magnifyingobservation system;

FIG. 2A is a perspective view illustrating an appearance of a magnifyingobservation apparatus;

FIG. 2B is a perspective view illustrating an appearance of a magnifyingobservation apparatus according to a modification when viewed from theleft;

FIG. 2C is a perspective view illustrating the appearance of themagnifying observation apparatus of FIG. 2B when viewed from the right;

FIG. 3 is a front sectional view illustrating an inside of a specimenchamber of the magnifying observation apparatus;

FIG. 4 is a sectional side view when viewed from line IV-IV of FIG. 3;

FIG. 5 is a sectional view taken along line V-V of FIG. 4;

FIG. 6 is a partially sectional perspective view illustrating ahorizontal surface moving mechanism of a specimen stage when viewed fromthe obliquely right front;

FIG. 7 is a partially sectional plan view illustrating the horizontalsurface moving mechanism of FIG. 6 when viewed from above;

FIG. 8 is a partially sectional perspective view illustrating thehorizontal surface moving mechanism of FIG. 6 when viewed from theobliquely right back;

FIG. 9 is a schematic view illustrating a state in which an opticalimaging device is connected while switched to a SEM or a stand;

FIG. 10 is a schematic front view illustrating a distance between eachobservation device and the specimen stage;

FIG. 11 is a schematic side view illustrating divisions of a rotationpart and a fixed part;

FIG. 12 is a sectional side view schematically illustrating a specimenchamber in which a cover portion is provided in the fixed part;

FIG. 13A is a sectional side view schematically illustrating a state inwhich the specimen chamber is closed by the cover portion integratedwith the specimen stage;

FIG. 13B is a sectional side view schematically illustrating a state inwhich the cover portion of the specimen chamber of FIG. 13A is opened;

FIG. 14 is a schematic perspective view illustrating an example of thespecimen chamber in which only one side of the body portion is rotated;

FIG. 15 is a schematic perspective view illustrating an example of thespecimen chamber in which only an intermediate part of the body portionis rotated;

FIG. 16 is a sectional side view schematically illustrating the specimenchamber in which a body portion is formed into a semicircular shape;

FIGS. 17A to 17C are schematic diagrams conceptually illustratingrotatable ranges of the optical imaging device and an electron beamimaging device, where FIG. 17A illustrates an overlapping rotating rangeof the electron beam imaging device and the optical imaging device, FIG.17B illustrates the rotatable range of the electron beam imaging device,and FIG. 17C illustrates the rotatable range of the optical imagingdevice;

FIG. 18 is a block diagram illustrating a configuration of the electronbeam imaging device;

FIG. 19 is a block diagram illustrating a configuration of an electronlens system of an electrostatic lens;

FIG. 20 is a block diagram illustrating a configuration of an electronlens system of an electromagnetic lens;

FIG. 21A is a block diagram illustrating a configuration of an opticallens system of the optical imaging device;

FIG. 21B is a block diagram illustrating an optical imaging system inwhich the optical imaging device is controlled by an informationprocessing section;

FIG. 22A is a schematic sectional view illustrating a relative movementof the specimen stage and an observation device in the specimen chamber;

FIG. 22B is a schematic sectional view illustrating a state in which theobservation device is rotationally moved in the specimen chamber of FIG.22A;

FIG. 23A is a schematic sectional view illustrating the specimen stagemoved by a conventional eucentric structure;

FIG. 23B is a schematic sectional view illustrating a state in which thespecimen stage is tilted in the specimen chamber of FIG. 23A;

FIG. 24 is a schematic sectional view of the specimen chamberillustrating a state in which the specimen stage is lowered to align asurface on which a specimen is placed or an observation surface with arotation axis;

FIG. 25 is a schematic side view illustrating a positional relationshipbetween a focal position of an electron lens and a rotation axis;

FIG. 26 is a schematic side view illustrating a positional relationshipbetween a focal position of an optical lens and the rotation axis;

FIG. 27 is a schematic diagram illustrating a visual field range and adisplay range of the electron beam imaging device;

FIG. 28 is a schematic diagram illustrating a visual field range and adisplay range of the optical imaging device;

FIG. 29 is a block diagram of a magnifying observation apparatus havinga magnifying power conversion function;

FIG. 30 is a sectional view of an optical magnifying power readingsection;

FIG. 31 is an image diagram illustrating a display example of amagnifying power range display section;

FIG. 32 is an image diagram illustrating an example of an electronmicroscope image that becomes an original of image synthesis;

FIG. 33 is an image diagram illustrating an example of an optical imagethat becomes an original of the image synthesis;

FIG. 34 is an image diagram illustrating an example of a synthetic imagein which pieces of information on pixels of FIGS. 32 and 33 aresynthesized;

FIG. 35 is an image diagram illustrating a display example of a displaysection in which an electron microscope image display range and anoptical image display range are provided;

FIG. 36 is an image diagram illustrating a display example of a displaysection in which a predetermined magnifying power display section isprovided;

FIG. 37 is a block diagram of a magnifying observation apparatusincluding a display switching section;

FIG. 38 is a schematic sectional view illustrating a configuration of aspecimen chamber including a rotating type moving mechanism;

FIG. 39 is a schematic sectional view illustrating a specimen chamber inwhich observation devices can be switched in a circling manner;

FIG. 40 is a schematic sectional view illustrating a specimen chamber inwhich the observation devices can be switched in a translation manner;

FIG. 41 is a schematic sectional view illustrating a specimen chamber inwhich the observation devices can be switched by translating thespecimen stage;

FIG. 42 is a schematic sectional view illustrating a specimen chamber inwhich the observation devices can be switched by tilting the specimenstage;

FIG. 43 is a schematic sectional view illustrating a specimen chamber inwhich the observation devices can be switched by selecting an opticalaxis of the observation device using a half mirror; and

FIG. 44 is a schematic diagram illustrating a magnifying observationapparatus in which a separate optical microscope and an electronmicroscope are controlled with a common controller.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the present invention will be described withreference to the drawings. It should be noted that the embodimentsillustrate a magnifying observation apparatus in order to specify thetechnical concept of the invention, and the present invention is notlimited to the magnifying observation apparatus described below. Themember described in the claims of the present invention is not limitedto the member of the embodiment. In particular, the scope of theinvention is not limited to the sizes, materials, shapes, and relativedisposition of the components are described merely as illustrativeexamples in the embodiments unless otherwise noted. The sizes andpositional relationship of the members illustrated in each of thedrawings may be exaggerated for the purpose of clear explanation. In thefollowing description, the same name or reference numeral denote thesame or equivalent member, and the detailed description thereof isappropriately omitted. In each element constituting the invention, aplurality of elements may include the same member, and one member mayact as a plurality of elements, or the function of one member may beshared by a plurality of members.

Herein, a magnifying observation apparatus and a computer, a printer, anexternal storage device, and other peripherals, which are connected tothe magnifying observation apparatus to perform operation, control,input/output, display, and other pieces of processing, conductcommunication with each other by being electrically connected throughIEEE 1394, RS-232x, RS-422, RS-423, RS-485, serial connection such asUSB, parallel connection, and a network such as 10BASE-T, 100BASE-TX,and 1000BASE-T. The connection is not limited to a physical connectionin which a wire is used, but a wireless LAN such as IEEE802.1x and awireless connection such as Bluetooth (registered trademark) in whichradio wave, infrared ray, and optical communication are used may also beutilized. A memory card, a magnetic disk, an optical disk, amagneto-optical disk, and a semiconductor memory can be used as arecording medium in order to store observation image data and setting.

As used herein, the electron microscope image means a monochrome imagethat is obtained by an electron beam imaging device of an electronmicroscope to mainly include luminance information on an observationtarget and displayed by shades. The optical image means a color imagethat is obtained by an optical imaging device with visible light orultraviolet light to mainly include color information. In the opticalimage, an infrared observation image obtained by an infrared camera canbe used in addition to a visible-light observation image obtained by avisible-light camera. As described below, the electron microscope imagecan be colored based on the color information on the optical image. “Theelectron beam imaging device or the optical imaging device obtains theimage” generally means that the image is obtained with the electron beamimaging device or the optical imaging device. However, “the electronbeam imaging device or the optical imaging device obtains the image”also means a concept that the image obtained by the other member iscaptured in the electron microscope. The meaning of obtaining the imageincludes such a concept.

In the following embodiments, a SEM that is one of electron microscopesis described as an implementation example of the magnifying observationapparatus of the present invention. However, the present invention canalso be applied to a TEM, a STEM, and other charged particle beamapparatuses. In such cases, the electron beam imaging device can bereplaced with a charged particle beam imaging device. The presentinvention can also be applied to a near field microscope, an atomicforce microscope, and an electrostatic force microscope. Further, theoptical imaging device of the present invention can also applied to anoptical microscope, a laser microscope, a digital microscope, and thelike.

FIGS. 1 to 8 illustrate a magnifying observation apparatus according toan embodiment of the present invention. FIG. 1 is a schematic diagramillustrating an outline of a magnifying observation system, FIG. 2A is aperspective view illustrating an appearance of a magnifying observationapparatus, FIG. 2B is a perspective view illustrating an appearance of amagnifying observation apparatus according to a modification, FIG. 2C isa perspective view illustrating the appearance of the magnifyingobservation apparatus of FIG. 2B when viewed from the right, FIG. 3 is afront sectional view illustrating an inside of a specimen chamber of themagnifying observation apparatus, FIG. 4 is a sectional side view whenviewed from line IV-IV of FIG. 3, FIG. 5 is a sectional view taken alongline V-V of FIG. 4, FIG. 6 is a partially sectional perspective viewillustrating a horizontal surface moving mechanism of a specimen stagewhen viewed from the obliquely right front, FIG. 7 is a partiallysectional plan view illustrating the horizontal surface moving mechanismof FIG. 6 when viewed from above, and FIG. 8 is a partially sectionalperspective view illustrating the horizontal surface moving mechanism ofFIG. 6 when viewed from the obliquely right back.

(Magnifying Observation System)

A magnifying observation system 1000 illustrated in FIG. 1 includes amagnifying observation apparatus 100, a decompression pump VP, apower-supply unit PU, and display section 2. The magnifying observationapparatus 100 includes a chamber unit 14 that maintains a specimen in anairtight manner and a decompression unit 15 that decompresses an insideof a specimen chamber 21. An electron beam imaging device 11 and anoptical imaging device 12 are mounted as an observation device 10 on thechamber unit 14. The decompression unit 15 is connected to the externaldecompression pump VP to constitute an evacuation system pump 70 thatdecompresses the inside of the specimen chamber 21 to a predeterminedvacuum such as high vacuum and low vacuum. Each observation device 10 isconnected to the display section 2 to transmit obtained image data tothe display section 2. The display section 2 includes a display, and anelectron microscope image obtained by the electron beam imaging device11 or an optical image obtained by the optical imaging device 12 can bedisplayed on the display.

(Power-Supply Unit PU)

A controller 1, the magnifying observation apparatus 100, and thedecompression pump VP are connected to the power-supply unit PU. Thepower-supply unit PU is connected to an external commercial power source(not illustrated) to supply electric power to the magnifying observationapparatus 100 and the like. In this example, based on an instructionfrom the controller 1, the power-supply unit PU supplies a predeterminedvoltage to the magnifying observation apparatus 100, action of themagnifying observation apparatus 100 is controlled by the controller 1,and the obtained image is displayed in the display section 2.

(Controller 1)

In addition to a dedicated device, a general-purpose computer in which amagnifying observation apparatus operation program is installed can beused as the controller 1. An external console CS that operates thecontroller 1 and the display section 2, and a high-acceleration voltageunit HU that applies a high acceleration voltage to an electron gun 47of the electron beam imaging device 11 can be attached if needed. In theexample of FIG. 1, the controller 1 controls the magnifying observationapparatus 100 through the power-supply unit PU. Alternatively, themagnifying observation apparatus 100 may be directly controlled whilethe power-supply unit is integrated the controller.

(Display Section 2)

In FIG. 1, the controller 1 includes the display section 2. The displaysection 2 includes a display portion 102 on which the electronmicroscope image and the optical image are displayed. The images cansimultaneously be displayed on one screen, or can be displayed whilebeing switched from one another. The switching of the display ismanually performed from the console CS. A monitor such as a CRT, an LCD,and an organic EL can be used as the display section 2. In the exampleof FIG. 1, the display section 2 and the controller 1 are integrallyconfigured. Alternatively, the display section 2 and the controller 1may separately be configured. The console CS may also be incorporated inthe controller 1 or the display section 2. For example, a touch-paneldisplay section can be used. A connection example of each member isillustrated in FIG. 1 by way of example. Alternatively, a differentconnection mode or wiring can be utilized. Obviously, each member can beconnected in a wireless manner if needed.

The magnifying observation system 1000 of FIG. 1 is a system thatcombines magnifying observation in which an optical lens such as adigital microscope is used and electron microscope observation in whichan electron microscope such as a SEM is used. That is, the opticalimaging device 12 is added inside the specimen chamber 21 of theelectron microscope. The optical imaging device 12 as a firstobservation device obtains an optical image with visible light orinfrared light. For example, an optical microscope and an opticalcamera, in which the light having a visible wavelength or an infraredwavelength is used, can be used as the optical imaging device 12. A usercan arbitrarily use the obtained optical image. For example, the opticalimage is used as an extensive image to search a visual field duringobservation of an electron microscope image such as a SEM image, or theoptical image can be used for the auxiliary purpose of electron beamobservation such as a confirmation of an observation target specimen.The plurality of imaging systems, i.e., the observation device 10including the electron beam imaging device 11 that obtains the imagewith a charged particle such as an electron beam and the optical imagingdevice 12 that obtains the image with the visible light, is configuredto switch between the electron beam imaging device 11 and the opticalimaging device 12.

In the observation device 10, as illustrated in FIG. 9, the opticalimaging device 12 is demounted from the magnifying observation apparatus100 constituting the SEM and connected to a digital microscope stand ST,which allows the observation of the specimen placed on a stage of thestand ST. From the standpoint of the magnifying observation system suchas the digital microscope in which the optical lens is used, it is seenthat the configuration of FIG. 9 allows the electron beam imaging device11 such as the SEM to be connected as one of exchangeable head portions.That is, in the conventional digital microscope, only the opticalobservation device can be mainly connected as a camera unit or a lensunit like the stand type camera unit illustrated in FIG. 9. On the otherhand, in this embodiment, the electron beam imaging device 11 such asthe SEM can be connected, and the optical imaging device 12 can also beused as the camera unit that obtains the optical image in the specimenchamber 21 in which the electron beam imaging device 11 is provided. Insuch cases, the magnifying observation apparatus 100 including theelectron beam imaging device 11 of FIG. 9 constitutes one of theexchangeable head portions of the magnifying observation system.Therefore, the head portion such as the SEM and the optical lens isselectively mounted as one of the exchangeable camera or lens that areused in the magnifying observation system, the observation can beperformed while the proper observation device is connected according tothe desired application, a magnifying observation available range can beexpanded not only to the optical system but also to the electronmicroscope system, and various magnification observations can beimplemented.

On the other hand, from the standpoint of the magnifying observationapparatus including the electron beam imaging device 11, it can be seenthat the digital microscope is added to the magnifying observationapparatus. In either case, advantageously the optical image and theelectron microscope image can be obtained for the same specimen.Particularly, the optical image and the electron microscope image, whichare obtained by the different observation devices, can be compared inthe same visual field at the same magnifying power. Therefore, theobservation can be performed from various viewpoints by taking advantageof each observation image, and information amount obtained by themagnification observation can dramatically be increased.

(Observation Device 10)

The magnifying observation apparatus includes a plurality of observationdevices 10 that observe the specimen in the specimen chamber 21. In themagnifying observation apparatus 100 illustrated in FIG. 2A, theelectron beam imaging device 11 as the first observation device that canobtain the electron microscope image and the optical imaging device 12as the second observation device that can obtain the optical image arefixed while projected from a body portion 24. Each imaging device isconfigured such that a display switching section 36 can switch betweenuse and non-use. In the example of FIG. 2A, a push button is provided asthe display switching section 36 in a cylindrical shaped outer surfaceof the body portion 24. In addition to the alternation of the use of thefirst and second imaging devices, the first and second imaging devicesmay be configured to be simultaneously used. In the example of FIG. 2A,although the optical imaging device 12 is disposed on the right side ofthe electron beam imaging device 11, the similar effect is also obtainedeven if the electron beam imaging device 11 and the optical imagingdevice 12 are switched around.

(Magnifying Power Adjusting Section)

Each observation device 10 includes a magnifying power adjusting sectionthat adjusts the magnifying power. Specifically, the electron beamimaging device 11 includes an electron microscope magnifying poweradjusting section 68 that adjusts an electron microscope magnifyingpower. On the other hand, the optical imaging device 12 includes anoptical magnifying power adjusting section 95 that adjusts an opticalmagnifying power. For example, each magnifying power adjusting sectionadjusts the magnifying power by rotating a ring rotatably provided in anouter circumference of each barrel as illustrated in FIG. 2A.Particularly, similarly to the optical magnifying power adjustingsection 95, the electron microscope magnifying power adjusting section68 is formed into a ring shape in which the electron microscopemagnifying power adjusting section 68 is rotated around the barrel, anoperation feeling of magnifying power adjustment on each observationdevice is unified to provide an excellent user interface. Preferably,antislip finishing is provided in a surface of each ring. For example,the electron microscope magnifying power adjusting section 68 has anadjustable magnifying power range of 20 times to 10000 times. Forexample, the optical magnifying power adjusting section 95 has theadjustable magnifying power range of 50 times to 500 times. Ahigher-magnifying-power image can also be obtained when a digital zoomis used in combination with an optical zoom.

(Focus Adjusting Section)

Each observation device 10 may include a focus adjusting section thatadjusts a focal distance along each optical axis. For example, theelectron beam imaging device 11 includes a microscopic focus adjustingsection 37 that adjusts the focal distance along the optical axisthereof, and the optical imaging device 12 includes an optical focusadjusting section 38 that adjusts the focal distance along the opticalaxis thereof. The optical focus adjusting section 38 mechanically movesup and down the optical lens in an optical axis direction to adjust thefocal position. In the example of FIG. 2A, a dial knob is provided asthe focus adjusting section near each observation device, and the focalposition can be adjusted by a rotation amount of the knob. Herein, anaxis on which electron gun irradiates the specimen with the electronbeam when the electron beam imaging device 11 obtains the electronmicroscope image is referred to as an “optical axis”. In more detail,the “optical axis” is that an optical path of the electron beamirradiated from the electron gun has the smallest of an aberration oflens formed by a magnetic field or an electrical field or is a path tobe provided the most efficient electron beam

The color optical image including color information can be obtained byusing the optical imaging device 12 in combination with the electronbeam imaging device 11 in addition to the mainly-monochrome electronmicroscope image without color information. In addition to the visiblelight observation image in which the visible light or ultraviolet lightis used, an infrared observation image obtained with an infrared cameracan also be used in the optical imaging device 12. The electronmicroscope image can be colored based on the color information of theoptical image. For example, a high-magnifying-power, high-accuracy colorimage can be obtained by combining the optical image with the electronmicroscope image.

(Magnifying Observation Apparatus 100)

Next, the outline of the magnifying observation apparatus 100 will bedescribed. As illustrated in FIG. 2A to FIG. 4, an appearance of themagnifying observation apparatus 100 has a shape in which the box-shapeddecompression unit 15 is coupled to the cylindrical chamber unit 14. Asillustrated in FIG. 4, the chamber unit 14 is placed on the flat-platebase portion 22. A fixing plate 23 is mounted on an upper surface of thebase portion 22 so as to be projected in a vertical posture. The fixingplate 23 acts as an end-face plate that closes one of opening ends ofthe body portion 24. The decompression unit 15 is mounted on a backsurface of the fixing plate 23. A rotating device 30 that rotates thebody portion 24 is provided in a front surface of the fixing plate 23.In the configuration of FIG. 4, the fixing plate 23 closes one-side endface of the body portion 24 in an airtight manner while the rotatingdevice 30 is interposed therebetween, and the body portion 24 isrotatable while the specimen chamber 21 is maintained in thedecompression state. In order to permit the rotation of the body portion24, the fixing plate 23 is separated from the base portion 22 so as tofloat on the base portion 22 while retaining the body portion 24 on thebase portion 22 in a cantilever manner, and a gap is provided betweenthe base portion 22 and the body portion 24. An opening edge of the bodyportion 24 is not in contact with the fixing plate 23, and a gap isprovided such that the rotation of the body portion 24 is notobstructed.

The chamber unit 14 includes the body portion 24 and a pair of end-faceplates and constitutes a main body portion of the magnifying observationapparatus 100. An outer shape of the body portion 24 is formed into asubstantially cylindrical shape. An internal space of the body portion24 is closed in the airtight manner by the two end-face plates toconstitute the specimen chamber 21 that can be decompressed. One of theend-face plates constitutes an opening and closing cover portion 27while the other end-face plate constitutes the fixing plate 23 mountedon the body portion 24, thereby closing the specimen chamber 21 in theairtight manner. As illustrated in a sectional view in FIG. 5, a suctionport 25 is opened in the fixing plate 23 in order to suck air in thespecimen chamber 21 to the decompression unit 15. A secondary electrondetector 61 and an in-specimen-chamber observation device 13, to bedescribed later, are provided in the fixing plate 23.

(Decompression Unit 15)

The specimen chamber 21 is connected to the decompression unit 15through the suction port 25. The decompression unit 15 constitutes anevacuation system to implement a decompression environment such that theelectron beam of the accelerated electron reaches the specimen withoutlosing energy in passing through a gas component as much as possible. Arotary pump, an oil diffusion pump, a Turbo-Molecular Pump (TPM), andthe like can be used as the decompression unit 15 to adjust the specimenchamber 21 to the desired vacuum from the high vacuum to the low vacuum.For example, the vacuum can be adjusted in a range of 10⁻⁶ Torr to 10⁻¹⁰Torr. The decompression unit 15 is coupled to the back surface of thechamber unit 14 in the airtight manner. Preferably, the suction port 25is provided in the fixing plate 23 that is the fixed part. However,obviously the suction port 25 may be provided on a rotation part side.

(Decompression Unit Operation Panel 16)

A decompression unit operation panel 16 is provided in the decompressionunit 15 in order to operate the action of the decompression unit. In theexample of FIG. 2A, the decompression unit operation panel 16 isprovided beside the body portion 24, and evacuation or venting isstarted by button operation. An indicator is provided in thedecompression unit operation panel 16 to indicate an underway evacuationoperation or completion of the operation. In this example, two LEDs areprovided as the indicator, the state of the specimen chamber 21 isdisplayed by a combination of lighting patterns while divided into fourstates, i.e., an atmospheric state, underway evacuation, the vacuumstate, and underway venting.

(Leg Portion 26)

In the magnifying observation apparatus 100, leg portions 26 areprojected from four corners of a bottom surface of the base portion 22.The magnifying observation apparatus 100 is horizontally installed on aground surface with the leg portions 26 interposed therebetween.Preferably, an adjusting section that can adjust a level of each legportion 26 is provided in the leg portion 26. Therefore, advantageouslya specimen stage 33 is maintained in a horizontal posture to stablyperform the magnification observation irrespective of a tilt of theground surface. For example, a well-known configuration such as amechanism that can adjust a projection amount of the adjusting sectionby progression of a screw can appropriately be used as the adjustingsection. As illustrated in a side view in FIG. 4, the leg portion 26 isprovided in the base portion 22 on the side of the chamber unit 14.Alternatively, the leg portions may be provided in the decompressionunit 15.

(Body Portion 24)

The body portion 24 has a hollow cylindrical shape, and both end facesof the body portion 24 is sealed by the end-face plates to form theairtight specimen chamber 21. At least one of the end-face platesconstitutes the opening and closing cover portion 27. The opticalimaging device 12 and the electron beam imaging device 11 are mountedonto the cylindrical shaped outer surface of the body portion 24.Specifically, the electron beam imaging device 11 is mounted in a firstposition 41, and the optical imaging device 12 is mounted in a secondposition 42 separated from the first position 41.

The optical imaging device 12 and the electron beam imaging device 11are configured to be formed into the cylindrical shape in which the lensis incorporated. In the optical imaging device 12, a plurality ofoptical lenses are incorporated in the cylindrical optical lens barrel.Similarly, in the electron beam imaging device 11, the electron lens isincorporated in the electron lens barrel. As illustrated in a sectionalview in FIG. 3, the optical imaging device 12 and the electron beamimaging device 11 are mounted on the outer surface of the body portion24 while radially projected from the center axis of the specimen chamber21 whose inside is formed into the cylindrical shape. In other words,the electron lens barrel and the optical lens barrel of the observationdevices 10 are fixed while oriented toward the rotation centers,respectively, and the optical axis of the electron gun 47 of theelectron beam imaging device 11 and the optical axis of the opticalimaging device 12 are radially extended about the rotation axis of therotating device 30.

(Cover Portion 27)

One of the end-face plates constitutes the opening and closing coverportion 27. As illustrated in the side view in FIG. 4, the cover portion27 includes a disc part 28 that closes the end face of the body portion24 and an arm 29 that journals the disc part 28 for the rotation of thedisc part 28. In FIG. 4, the left side is the front surface side. Asillustrated in FIG. 4, a lower end of the arm 29 is pivoted at a leadingend of the base portion 22 by a hinge, the disc part 28 is openeddownward by pulling down the arm 29, and the disc part 28 is located inthe end face of the body portion 24 to close the body portion 24 bymaking the arm 29 upright. The user can place the specimen on thespecimen stage 33 provided in the specimen chamber 21 while the coverportion 27 is opened. In the example illustrated in FIG. 6, the arm 29that journals the center of the cover portion 27 is mounted on theleading end of the base portion 22 in a bendable manner. Therefore, thearm 29 is pulled down frontward, and the cover portion 27 can be locatedin an opened position. According to such a structure, irrespective ofthe rotation position of the body portion 24, the opening and closingdirection of the cover portion 27 can be constantly kept downward whilethe cover portion 27 is rotated while being in close contact with thebody portion 24.

The end face of the body portion 24 is opened and closed by the coverportion 27, so that advantageously the inside of the specimen chamber 21can largely be opened to easily set a large-size specimen. Particularly,in combination with the configuration in which the specimen stage 33 isnot tilted, it is only necessary to simply place the specimen on thespecimen stage 33, and it is not necessary to fix the specimen on thespecimen stage 33 so as not to slip. Therefore, advantageously the workto take in and out the specimen and the work to place the specimen cansimply be performed.

In order to easily place the specimen on the specimen stage 33, a slidetype in which the specimen stage 33 is pulled out frontward while thecover portion 27 is opened can also be adopted (for example, see FIGS.13A and 13B, to be described later). Therefore, the user can easilyaccess the specimen stage 33. In addition to the cover portion 27, theend-face plate and the body portion 24 are made of asufficiently-durable member that can maintain the high vacuum.

(Fixed Part)

In the body portion 24, at least part of the cylindrical shaped outersurface can be rotated by the rotating device 30. Therefore, the bodyportion 24 and the end-face plate are divided into a rotation part thatis rotated in association with rotation motion of the body portion 24and a fixed part that remains still without the rotation. In otherwords, the body portion 24 and the end-face plate are divided into thefixed part and the rotation part by the rotating device 30. For example,a horizontal surface moving mechanism 74 and a height adjustingmechanism 80, which are a specimen stage driving section 34 that drivesthe specimen stage 33, the cover portion 27, the in-specimen-chamberobservation device 13, the base portion 22, and the fixing plate 23constitute the fixed part. On the other hand, each observation device 10and a light source port 97 of an illumination portion that is associatedwith or cooperates with the observation device 10 are provided on therotation part side.

(Rotating Device 30)

The body portion 24 includes the rotating device 30 as a moving devicethat can move each observation device such that the optical axisdirection of one of the observation devices is aligned with the opticalaxis direction of the other observation device. The rotating device 30rotates the side surface, to which the observation devices 10 are fixed,along the circumference about the center axis of the cylindrical bodyportion 24. For example, a mechanism in which a bearing or a gearprovided in the rotation axis direction of the body portion 24 isrotated by engagement with a gear provided on the side of the baseportion 22 or decompression unit 15 that is the fixed side can be usedas the rotating device 30. An external force necessary to rotate therotating device 30, namely, a resistance force against the rotation isset to a degree to which the user can manually rotate the rotatingdevice 30 and a degree to which the resistance force can maintain theposture when the user releases the user's hand from the rotating device30 while the body portion 24 is rotated such that the observation device10 becomes the desired position. An oil amount of the bearing and aweight of the gear are adjusted such that the resistance force andfrictional force of the rotation can be maintained. With such aconfiguration, the plurality of observation devices 10 can easily beswitched to the same position without generating the change of thevisual field. Because the observation device 10 can be tilted by therotating, advantageously tilt observation can simply be performed at thehigh magnifying power by a multi-angle mechanism.

As described above, the rotating plane in which the electron beamimaging device 11 rotates is substantially aligned with the rotatingplane in which the optical imaging device 12 rotates. Because theoptical axes of the imaging devices intersect each other, theobservation image of the same visual field can be obtained only byrotating one of the imaging devices to the position of the other imagingdevice. Therefore, advantageously the user operations, such as visualfield matching by the position switching and adjustment of the focalpoint, which switch to the different imaging device in order to performthe imaging in the same visual field can be performed extremely easily.

The specimen stage 33 is fixed onto the fixed part side, because thespecimen is in a fixed posture while the observation device 10 isrotated by the rotating device 30. In the example of FIG. 4, thehorizontal surface moving mechanism 74 and the height adjustingmechanism 80, which are the specimen stage driving section 34 thatdrives the specimen stage 33, are mounted on the back surface of thebody portion 24 with the end-face plate interposed therebetween.

Conventionally, because the side of the specimen stage 33 is rotated ortilted, it is not easy for the user to recognize a positionalrelationship between the camera and the specimen when a viewpoint ischanged, and confusion is frequently generated in the moving directionor the like. On the other hand, in the present embodiment, because ofthe natural observation method in which the observation target is fixedwhile the viewpoint of the viewer is changed, advantageously thepositional relationship is physically easily recognized,misunderstanding or confusion is hardly generated in the adjustment workin moving or changing the viewpoint, and it is easy to understand evenfor a beginner.

The optical imaging device 12 and the electron beam imaging device 11,which are the observation devices 10, can simultaneously be moved byrotating the side surface of the body portion 24. Advantageously, themechanisms that move the two observation devices 10 can be simplified asone rotating device 30 that functions as the moving mechanisms for theoptical imaging device 12 and the electron beam imaging device 11. Theobservation devices 10 can easily be switched to the same position bythe rotation, and the specimen is immobilized in the position of therotation axis, whereby the change of the visual field is not generated.FIG. 10 is a schematic front view illustrating a distance between eachobservation device 10 and the specimen stage 33. As illustrated in FIG.10, in the observation devices 10 of the optical imaging device 12 andthe electron beam imaging device 11, because the distance to thespecimen located on the rotation axis can substantially be kept constantby a rotational transfer, once the focal distance is adjusted, thefocused state is always obtained even if the position is changed.Therefore, there is realized an environment suitable for in-focus tiltobservation in which only a rotation angle, namely, the viewpoint can bechanged.

Preferably, the cover portion 27 is fixed onto the fixed part side inthe opening and closing manner. For example, as illustrated in the sideview in FIG. 4, the rotation axis of the disc part 28 is journaled onthe arm 29 while the disc part 28 of the cover portion 27 is detachablymounted on the opened end of the body portion 24, and the lower end ofthe arm 29 is mounted on the leading end of the base portion 22 in thebendable manner. Therefore, as described above, the direction in whichthe cover portion 27 is opened and closed can be kept constantirrespective of the rotation position of the body portion 24. In thiscase, the cover portion 27 closes the front surface side of the end faceof the body portion 24, the end-face plate of the back surface is fixedwhile integrated with the body portion 24, and the specimen stagedriving section 34 that drives the specimen stage 33 is mounted on thedecompression unit 15 that is the fixed part so as to penetrate part ofthe body portion 24. That is, in this example, the disc part 28 of thecover portion 27 is integrated with the rotation part while the bodyportion 24 is closed, and the arm 29 is mounted on the fixed part. Atension spring 135 is provided near a hinge portion 138 that is a foldedportion of the arm 29 and the base portion 22. The tension spring 135biases the hinge portion 138 in the direction in which the hinge portion138 is easy to fold. That is, the tension spring 135 enables the arm 29to be easily made upright from a horizontal posture in the opened stateto a vertical posture in the closed state. The tension spring 135, whichis an unlock mechanism that unlocks a lock state of a retainingmechanism 140 even after the vertical posture, also biases the arm 29onto the side of the body portion 24.

When the cover portion 27 is fixed onto the rotation part side, theopening and closing direction of the cover portion 27 varies accordingto the rotation position of the body portion 24, and unfortunately theuser is required to confirm the opening and closing direction in eachcase. When the cover portion 27 is made of heavy metal having highrigidity, it may be difficult for the user to manually open and closethe cover portion 27 depending on the direction of the cover portion 27,or a load on the hinge portion that supports the opening and closing ofthe cover portion 27 may be increased depending on the direction of thecover portion 27. Therefore, in order to avoid the change of the openingand closing posture, the fixed position of the cover portion 27 iseffectively provided on the fixed part side. Additionally, the openingand closing of the cover portion 27 are always oriented toward aconstant direction, which allows the opening and closing structure ofthe cover portion 27 to be advantageously simplified.

However, in the present embodiment, there is no limitation to theopening and closing direction of the cover portion 27, and a system inwhich the cover portion 27 is opened and closed upward may be adoptedwhen the cover portion 27 is laterally opened and closed, or whensufficient strength is maintained. Alternatively, a slide system inwhich the cover portion 27 is moved outward in the rotation axisdirection may also be adopted. In this case, the cover portion 27 ispulled out frontward while maintained in parallel with the bottomsurface of the body portion 24. With this configuration, advantageouslythe cover portion 27 and the specimen stage 33 can simultaneously bepulled out to facilitate the access to the specimen stage 33 asdescribed above. Irrespective of the opening and closing system of thecover portion 27, the specimen stage 33 alone may be configured to bepulled out to the outside of the specimen chamber 21. For example, thespecimen stage 33 and the arm of the specimen stage driving section 34that drives the specimen stage 33 are freely projected onto the frontside, which allows the implementation of the configuration in which thespecimen stage 33 is pulled out.

As described later, the specimen stage 33 can be moved and rotated in aplane while the horizontal posture is maintained such that the specimenstage 33 is not tilted or oscillated. As used herein, “fixing” thespecimen stage 33 in the horizontal posture means that the specimenstage 33 is not tilted or oscillated about the rotation axis withrespect to the body portion 24. That is, sliding the specimen stage 33in the rotation axis direction is included in the concept of “fixing”.

(Modification of Rotating Device)

FIG. 11 is a schematic side view mainly illustrating the division of theconfiguration of FIG. 4 into the rotation part and the fixed part. Inthis configuration, the whole of the body portion 24 rotates withrespect to one of the end-face plates (back surface side located on theright side in FIG. 11), and the rotating device 30 is provided betweenthe end-face plate and the body portion 24 to perform the rotating ofthe body portion 24. The rotation part such as the cover portion and thebody portion and the fixed part are not limited to such a configuration,but various modes can be utilized. FIGS. 12, 13A and 13B illustraterotating devices according to modifications. In FIGS. 12, 13A and 13B,FIG. 12 is a sectional side view schematically illustrating a specimenchamber 21B in which a cover portion 27B is provided in the fixed part,FIG. 13A illustrates a state in which a specimen chamber 21C is closedby a cover portion 27C integrated with a specimen stage 33C, and FIG.13B illustrates a state in which the cover portion 27C is opened. Forthe sake of convenience, the decompression unit and the like are omittedin FIGS. 12, 13A and 13B.

In the example of FIG. 12, the front surface side (left side in FIG. 12)of the body portion 24 is closed by the end-face plate, and the openingand closing cover portion 27B is provided on the back surface side(right side in FIG. 12). In this configuration, the cover portion 27Bconstitutes the fixed part that is not rotated by the rotation of thebody portion 24. In the examples of FIGS. 13A and 13B, the specimenstage 33C is integrally mounted on the cover portion 27C provided in thefixed part. In this configuration, as illustrated in FIGS. 13A and 13B,the specimen stage 33C is preferably mounted on the cover portion 27Cand the cover portion 27C is pulled out from the back surface of theapparatus, whereby the specimen stage 33C mounted on the cover portion27C is pulled out to the outside of the specimen chamber 21C while thecover portion 27C is opened. With this configuration, the access to thespecimen stage 33C is facilitated, and the specimen is easily placed,taken out, and exchanged.

Although the whole of the body portion is rotated in the examples ofFIGS. 11 and 12, only part of the body portion may be rotated. Forexample, as illustrated in the perspective view in FIG. 14, a bodyportion 24D is divided into two, one of the end-face plates (backsurface side on the right side in FIG. 14) constitutes the fixed part(illustrated by oblique lines in FIG. 14), and the other end-face plate(front surface side) constitutes the rotation part, thereby rotatingpart of the cylindrical shaped outer surface (front surface side). Inthe example illustrated in a perspective view in FIG. 15, a body portion24E is divided into three, both end faces constitute the fixed part(illustrated by oblique lines in FIG. 15), and only an intermediate partof the side surface, to which the observation device 10 is fixed, isslid. Therefore, advantageously the end-face plate and a cover portion27E constitute the fixed part side, and particularly the opening andclosing structure of the cover portion 27E can easily be formed.

In such configurations, when the fixed part is provided in part of theend-face plate or body portion 24, the fixed part supports the specimenstage driving section 34 that drives the specimen stage 33.Specifically, as illustrated in FIG. 4 and the like, the opening isprovided in the end-face plate, and the specimen stage driving section34 that drives the specimen stage 33 is provided inside the opening andon the fixing plate 23. That is, the arm of the specimen stage drivingsection 34 is inserted in the specimen chamber 21 from the opening thatis the fixed part, and the specimen stage 33 is supported at the leadingend of the arm while driven in X-, Y-, and Z-directions. In the exampleof FIG. 15, the specimen stage driving section 34 may be provided in thefront-surface-side end-face plate that is another fixed part.Alternatively, the body portion 24 and both the end-face plates may bejournaled about the rotation axis on the base portion 22. In this case,the specimen stage 33 can be supported only by part of the end-faceplate.

In any of the configurations, there is a demand for the structure inwhich the body portion 24 can be rotated in the airtight manner suchthat the decompression state can be maintained in the specimen chamber21 even if the rotating device is rotated. Particularly, the bodyportion 24 has a considerable weight because it includes the pluralityof observation devices 10, and the body portion 24 is rotated in thecantilever posture by the fixing plate 23. Therefore, a sufficientmechanical strength is also required. Therefore, in the exampleillustrated in FIG. 4, a crossed-roller bearing 31 having high rotationaccuracy and an excellent weight bearing resistance property is used asthe bearing in a rotation plane between the fixing plate 23 and the bodyportion 24, which constitute the end-face plate. Additionally, an O-ring32 is interposed in order to maintain the airtightness in the rotationplane. Therefore, the stable rotation mechanism can be implemented whilethe airtightness of the specimen chamber 21 is maintained in the bodyportion 24.

As used herein, it is not always necessary that the rotation and therotating mean the complete circular motion, but the rotation and therotating include an arc movement locus. For example, as illustrated in aschematic sectional side view in FIG. 16, a body portion 24F is formedinto a semicircular shape, and the electron beam imaging device 11 andthe optical imaging device 12 are moved along the curved side surface toenable the tilt observation to be performed in a specimen chamber 21F.Similarly, not only a complete cylinder but also a partial cylinder suchas a semicircular or an arc in section can be used as the cylindricalshaped outer surface of the body portion.

(Handgrip 35)

A handgrip 35 can also be provided in the body portion 24 so as tomanually easily rotate the body portion 24. Similarly to the observationdevice 10, the handgrip 35 illustrated in FIG. 2A is a chamber tilt knobthat is fixed while projected from the cylindrical shaped outer surfaceof the body portion 24. A grip part is provided at the leading end ofthe handgrip 35 such that the user can easily grasp the handgrip 35 byhand. The user can grasp the grip part of the handgrip 35 to rotate thebody portion 24 in the desired direction. Two handgrips 35 are providedspaced apart such that the user can grasp the handgrips 35 with bothhands. Preferably, the two handgrips 35 are provided on the outside ofthe positions, where the electron beam imaging device 11 and the opticalimaging device 12 that are two observation devices projected from theside surface of the body portion 24, such that the two observationdevices are sandwiched between the two handgrips 35. When the twoobservation devices are located between the handgrips 35, breakagecaused by the end portion of the circumferentially-projected observationdevice coming into contact with an external member during the rotatingis effectively prevented by the handgrips 35 disposed outside theobservation device. The handgrips 35 are projected longer than theelectron beam imaging device 11 and the optical imaging device 12, whichallows the protection effect of the observation devices to be furtherenhanced. Additionally, in the modification illustrated in FIGS. 2B and2C, the grip part provided at the leading end of a handgrip 35B is bentoutward, which allows the user to more easily grasp the handgrip 35B. Inaddition to the rod shape, the handgrip 35 may be formed into anL-shape, a U-shape, and a semicircular shape. Alternatively, only onehandgrip 35 may be provided. Alternatively, the observation device canalso be used as the handgrip when the observation device is mounted onthe body portion with the sufficient strength.

(Display Switching Section 36)

The magnifying observation apparatus includes the display switchingsection 36 that switches the imaging devices to be used. A hardwarechange-over switch can be cited as an example of the display switchingsection 36. In the example of FIG. 2A, push buttons are provided as thedisplay switching section 36 in front of the electron beam imagingdevice 11 and the optical imaging device 12 in the cylindrical shapedouter surface of the body portion 24. An indicating lamp 17 such as anLED lamp is provided in front of each button. In the display switchingsection 36, when one of the push buttons is pressed, the observationdevice in the back surface of the push button is selected, a movingimage displayed in real time on the display section is automaticallyswitched to the image obtained by the observation device, and thecorresponding indication lamp 17 is turned on to indicate that theobservation device is currently selected. In this manner, the user cansensuously be aware of the switching operation by the mechanicalswitching operation that presses the push button, and thecurrently-selected state can visually be recognized by pressed positionof the push button and the turning-on/turning-off of the indication lamp17. In the example of FIG. 2A, one of the push buttons can alternativelybe selected, and the non-selected push button is automatically turnedoff. In other words, one of the observation devices is selected by thedisplay switching section 36, and only the selected observation deviceis operated. Therefore, the two observation devices cannotsimultaneously be used. However, the two observation devices may beconfigured to be able to be simultaneously used in addition to theconfiguration in which the observation devices are alternately used.

In addition to the hardware operation that operates the change-overswitch provided in each observation device, software switching may beadopted when the observation devices are switched by the displayswitching section 36. For example, the selection state of theobservation device may automatically be switched when a window on whichthe observation image of the observation device to be selected isselected and activated on the screen of the display section.

In the display switching section 36, in addition to the hardwareconfiguration, a configuration may be adopted in which a switchinginstruction is provided in an electronic or software manner such as aconfiguration in which an operation program of the magnifyingobservation apparatus 100 is operated. Alternatively, a hardwarechange-over switch and a software change-over switch such as theoperation program may simultaneously be used. For example, when therotating device 30 rotates the body portion 24, the observation devices10 may automatically be switched. The change-over switch may be providedin the handgrip 35 for the rotating operation. Particularly, theoperation to switch the observation device 10 is frequently performed inthe timing the observation device 10 is physically moved, namely, therotating device 30 is operated. Therefore, the display switching section36 of the observation device 10 may be provided in the handgrip 35grasped by the user during the rotating, which allows the switchingoperation and the rotating operation to be substantially simultaneouslyperformed to improve the operability. For example, in the end face orside surface of a handle portion 35 b of the handgrip 35, a push buttonswitch is provided as the display switching section 36 in a positionwhere the user can easily press the push button switch by a thumb or anindex finger while grasping the handle portion 35 b. The push buttonswitch switches between the electron beam imaging device and the opticalimaging device in a toggle manner. Alternatively, a dedicated switchingbutton may be provided to switch to each observation device. Forexample, the change-over switch that switches to the observation devicedisposed on the right side can be provided in the right handgrip 35,that is, the change-over switch that switches to the optical imagingdevice can be provided in the optical imaging device. For example, thechange-over switch that switches to the observation device disposed onthe left side can be provided in the left handgrip 35, that is, thechange-over switch that switches to the electron beam imaging device canbe provided in the electron beam imaging device.

(Specimen Chamber 21)

A sealing structure is provided in the specimen chamber 21 so as to beable to maintain the decompression state. A port is opened in an innerwall of the specimen chamber 21 in order to dispose or connect variousmembers. Each port is sealed in an airtight manner such that the insideof the specimen chamber 21 can be maintained in the decompression state.For example, a gasket such as the O-ring is used at the coupling pointin order to implement the sealing structure.

(First Position 41 and Second Position 42)

In the observation device 10, the electron beam imaging device 11constituting the first observation device is mounted on the firstposition 41 in the cylindrical shaped outer surface of the body portion24, and the optical imaging device 12 constituting the secondobservation device is similarly mounted on the second position 42 nearthe first position 41 in the cylindrical shaped outer surface of thebody portion 24. In the example of FIG. 3, a distance between the firstposition 41 to which the electron beam imaging device 11 is fixed andthe second position 42 to which the optical imaging device 12 is fixedis a fixed value. That is, when the cylindrical body portion 24 isrotated, the optical imaging device 12 and the electron beam imagingdevice 11 rotate together. Therefore, the moving mechanisms of theobservation devices 10 can be simplified into one mechanism.

The second position 42 is a position in which the leading end of theoptical imaging device 12 does not interfere with the optical axis ofthe electron gun 47 of the electron beam imaging device 11. Preferably,the second position 42 is the position in which the leading end of theoptical imaging device 12 is brought close to the optical axis of theelectron gun 47 as much as possible while not interfering with theoptical axis of the electron gun 47. As illustrated in FIG. 3, theoptical imaging device 12 can be brought close to the electron beamimaging device 11, and as a result, a rotation amount necessary to turnto the positions of the observation devices 10 is suppressed to theminimum to smoothly and quickly perform the imaging position switchingwork. As illustrated in FIGS. 17A to 17C, by bringing the positions ofthe observation devices 10 close to each other, advantageously anoverlapping range (overlapping rotating range to be described later)between rotatable ranges of the observation devices 10 can be widened.

Therefore, an offset angle between the rotating center and the firstposition 41 or second position 42 is preferably made as small aspossible. Specifically, the offset angle ranges from 30° to 50°. In theexample of FIG. 3, the optical imaging device 12 and the electron beamimaging device 11 are mounted on the body portion 24 such that an angledifference of 40° is generated between the optical axis of the opticalimaging device 12 and the optical axis of the electron beam imagingdevice 11. The rotating device 30 can be rotated at the offset angle ormore, and therefore one of the observation devices can be rotated to theposition of the other observation device. In the rotating device 30, therotatable range is the maximum rotating range controlled by a rotatingcontrol section. The rotating device 30 can be rotated to a widerrotating range control value by releasing the rotating control section.

In this example, the electron beam imaging device 11 is mounted on thebody portion 24 in a non-exchangeable manner, and the optical imagingdevice 12 is detachably mounted on the body portion 24. Therefore, asillustrated in FIG. 9, the optical imaging device 12 can be detachedfrom the magnifying observation apparatus 100 to replace the opticalimaging device 12 with the digital microscope stand ST. An opticalimaging device mounting portion is provided in the second position 42 inorder to implement this detachably mounting structure.

(Optical Imaging Device Mounting Portion)

The optical imaging device mounting portion is provided in thecylindrical shaped outer surface of the body portion 24 in order todetachably mount the optical imaging device 12 at the second position42. The optical imaging device mounting portion includes a port that isopened so as to insert the optical lens barrel of the optical imagingdevice 12 therein, and a mount 39 is provided in the port in order tomount the optical imaging device 12. As illustrated in FIG. 3, the mount39 is formed into a cylindrical shape with a bottom, and an innerdiameter of the mount 39 is designed slightly larger than the outershape of the optical imaging device 12 such that the optical imagingdevice 12 can be mounted. A structure, such as a screw groove, to whichthe optical imaging device 12 is inserted and fixed, is provided in thecylindrical inner surface of the mount 39.

An opening window is provided in the bottom surface of the mount 39, anda translucent window is fitted in the opening window such that theoptical lens of the mounted optical imaging device 12 is not obstructed.The mount 39 is sealed by the O-ring such that the optical imagingdevice 12 can be mounted while the airtightness of the specimen chamber21 is maintained. The O-rings are provided in the coupling plane betweenthe mount 39 and the body portion 24 and the coupling plane between themount 39 and the translucent window, respectively. In the example ofFIG. 3, the optical imaging device mounting portion is vacuum-sealed byfour members, i.e., a first O-ring, the port, a second O-ring, and thetranslucent window.

The optical imaging device 12 is detachably mounted on the mount 39provided in the airtight manner in the cylindrical shaped outer surfaceof the body portion 24, which allows the optical observation to beperformed while the airtightness is maintained. A degree of freedom ofthe optical observation is dramatically increased since the opticalimaging device 12 mounted on the mount 39 can easily be exchanged.Particularly, in electron microscopes such as the conventional SEM,although there is an electron microscope including an optical lens thatcan perform the optical observation, in principle the optical lens issubsidiary used to search the visual field of the electron microscope,and there are few electron microscopes including full-fledged opticallens. On the other hand, in the present embodiment, because the opticallens can be exchanged, advantageously, options of the optical lenses arewidened in the optical observation combined with the electronmicroscope, and the degree of freedom of the observation is largelyincreased.

Conventionally, after the visual field is searched by the opticalimaging device 12, the fine observation is performed by the electronbeam imaging device 11. When the optical image and electron microscopeimage of the same visual field are displayed at the same magnifyingpower to perform contrast and switching by the combination of theoptical image and the electron microscope image, the work to align theoptical image and the electron microscope image to obtain the samevisual field becomes troublesome. On the other hand, in the presentembodiment, the magnifying powers of the optical imaging device 12 andthe electron microscope are overlapped, and the specimen is placed onthe rotation axis while the optical imaging device 12 and the electronmicroscope are rotated, so that the optical image and the electronmicroscope image can dramatically easily be obtained in the same visualfield range.

As illustrated in FIG. 3, the optical imaging device 12 and the electronbeam imaging device 11 are mounted on the first position 41 and thesecond position 42 while brought close to each other to a degree inwhich the optical imaging device 12 and the electron beam imaging device11 do not interfere with each other. Specifically, the leading end partof the observation device 10 may physically interfere in the specimenchamber 21, and one of the optical axes may be interrupted by the otherbarrel. Particularly, as illustrated in FIG. 3, because the electronbeam imaging device 11 is projected into the specimen chamber 21 whilethe optical imaging device 12 is mounted on the mount 39, an amount ofinvasion in the specimen chamber 21 is relatively small, and the opticalaxis may be obstructed by the leading end of the electron beam imagingdevice 11. Therefore, it is necessary that the optical imaging device 12and the electron beam imaging device 11 be spaced apart from each othersuch that the physical or optical interference is not generated.

On the other hand, when the optical imaging device 12 and the electronbeam imaging device 11 are excessively spaced apart, the moving distanceis lengthened when the body portion 24 is rotated and moved to thepositions of the optical imaging device 12 and the electron beam imagingdevice 11, and disadvantageously the overlapping of the loci in whichboth the observation devices 10 can be located, namely, the overlappingrotating range is narrowed. Therefore, the optical imaging device 12 andthe electron beam imaging device 11 are disposed close to each other toa degree in which the optical imaging device 12 and the electron beamimaging device 11 do not interfere with each other, the moving amount issuppressed to the minimum to eliminate the unnecessary moving amountwhen one of the observation devices 10 is moved to the observationposition of the other observation device 10, and advantageously theswitching can quickly be performed.

The positions to which the optical imaging device 12 and the electronbeam imaging device 11 are fixed are located substantially on the sameplane that is substantially orthogonal to the rotation axis of thecylindrical body portion 24. Therefore, because the optical imagingdevice 12 and the electron beam imaging device 11 are always moved inthe same circumference, the loci of the optical imaging device 12 andthe electron beam imaging device 11 are matched with each other, and theobservation images of the same visual field can be obtained.Particularly, because the moving ranges of the optical axes of theobservation devices 10 are matched with each other by substantiallymatching the rotating plane in which the electron beam imaging device 11rotates and the rotating plane in which the optical imaging device 12rotates, advantageously the observation images of the same visual fieldcan be obtained only by rotating one of the observation devices 10 tothe position of the other observation device 10, and user operations,such as the visual field matching and the focal point adjustment due tothe position switching, which switch to the different observation device10 in order to perform the imaging in the same visual field canextremely easily be performed.

The optical imaging device 12 and the electron beam imaging device 11are mounted on the same plane. Therefore, advantageously the length ofthe body portion 24 can be shortened, the compact apparatus can beachieved in the rotation axis direction, and the outer shape of themagnifying observation apparatus can be miniaturized. The tiltobservation can easily be performed at different tilt angles(observation angles) by the structure in which the side of the specimenstage 33 is mounted on tilt the side of the observation device 10, whichallows the high-magnifying-power tilt observation to be performed atmulti-angle.

Since the first position 41 to which the electron beam imaging device 11is fixed differs from the second position 42 to which the opticalimaging device 12 is fixed, the first position 41 differs from thesecond position 42 in the tilt angle at which the specimen image isobtained by each observation device 10. As a result, although theelectron microscope image and the optical image are simultaneouslyobtained at different tilt angles, the observation devices 10 can easilybe moved to the position of each observation device 10 by rotating thebody portion 24. That is, by the extremely simple operation of rotatingthe body portion 24, the electron beam imaging device 11 is quickly andcorrectly moved to the position in which the optical imaging device 12is located, or the optical imaging device 12 is quickly and correctlymoved to the position in which the electron beam imaging device 11 islocated. This is a great advantage compared to the conventional electronmicroscope.

According to the present embodiment, when the observation images at thesame tilt angle are to be obtained by the electron beam imaging device11 and the optical imaging device 12, after the observation image (forexample, optical image) is obtained by one of the observation devices(for example, optical imaging device 12), the cylindrical body portion24 is rotated to rotate the other observation device (for example,electron beam imaging device 11) to the position in which theobservation image is obtained by one of the observation devices. Sincethe rotating becomes the arc locus along the center axis of the rotationmotion, namely, the rotation axis, the optical axis of the observationdevice is always maintained anywhere in the posture in which the opticalaxis is oriented toward the rotation axis. Therefore, once the focaldistance is adjusted, the focusing operation is extremely easilyperformed since the focal distance is substantially maintained duringthe rotating.

In other words, when first picking up the observation image in one ofthe observation devices, if the focused position is also adjusted in theother observation device, the focused state is maintained before andafter the rotating, and the observation image can quickly be obtainedafter the rotating. Therefore, according to the present embodiment, theobservation images at the same position can quickly and easily beobtained using the two different observation devices 10.

As described above, in the configuration of FIGS. 3 and 17, the bodyportion 24 is rotated in order to observe the same visual field from thesame direction (tilt angle). Examples of a method of recognizing thatone of the observation devices is located in the position in which theother observation device is originally located include a method in whicha rotating position detection section such as a rotary encoder and anangle sensor is disposed in the body portion to electrically detect therotation angle and a method in which scales and marks are provided inthe body portion and the fixed side to visually recognize the rotationangle.

The two observation devices are mounted on the body portion 24 so as tohave the optical axis passing through the rotating center of therotating device 30 in any rotating position that can be provided by therotating device 30. The position of one of the observation devices (forexample, electron beam imaging device 11) is rotated and fixed to thedesired position of the observer using the rotating device 30, whichallows the magnification observation in a specific point of the specimenplaced on the specimen stage from the specific visual field direction.

As used in the present embodiment, the “substantially same observationposition” means as follows. After the image in the specific point of thespecimen placed on the specimen stage by one of the observation devicepositioned by the above-described technique, the other observationdevice (for example, optical imaging device 12) is rotated and fixed tothe rotating position in which one of the observation devices islocated, and the magnification observation is performed in the specificpoint of the specimen placed on the specimen stage from thesubstantially same specific visual field direction. In this case, the“substantially same observation position” means the position in whichone of the observation devices and the other observation device arepositioned.

The substantially same observation position is provided to the twoobservation devices, and the two observation devices obtain the imagesat the substantially same magnifying power. In such cases, it is assumedthat the position of the specimen stage and the position of thespecimen, placed on the specimen stage, relative to the specimen stageare substantially identical to each other. Therefore, the magnifyingpower of the image obtained by each observation device and the image inthe specific point of the specimen are enabled to improve the subsequentcomparative observation of the two images.

In other words, the observation visual field range in which the specimenis observed at the specific magnifying power from the specific visualfield direction by one of the observation devices is substantially equalto the observation visual field range in which the specimen is observedat the same magnifying power as the specific magnifying power from thesame direction as the specific visual field direction by the otherobservation device after the body portion 24 is rotated by the rotatingdevice 30 such that the specimen can be observed from the same directionas the specific visual field direction by the other observation device.Obviously, the substantially same observation position herein may notbecome the completely same observation position due to a mechanicalerror of the rotating device 30.

(Rotatable Range)

The ranges in which the optical imaging device 12 and the electron beamimaging device 11 can rotate are configured such that at least parts ofthe ranges overlap each other, namely, such that the observation devices10 can be moved to each position. FIGS. 17A to 17C are schematicdiagrams conceptually illustrating the ranges in which the opticalimaging device 12 and the electron beam imaging device 11 can rotate.FIG. 17A illustrates the overlapping rotating range of the electron beamimaging device 11 and the optical imaging device 12, FIG. 17Billustrates a rotatable range of the electron beam imaging device 11,and FIG. 17C illustrates a rotatable range of the optical imaging device12. In FIGS. 17A to 17C, a solid line indicates the rotatable range ofthe electron beam imaging device 11, and a broken line indicates therotatable range of the optical imaging device 12. As described above,because the optical imaging device 12 and the electron beam imagingdevice 11 rotate together by the rotation of the body portion 24, therotatable range in which each observation device 10 can rotate dependson the rotatable range of the body portion 24.

(Overlapping Rotating Range)

More accurately, an angle at which the angle difference between thefirst position 41 and the second position 42, namely, the offset angleis subtracted from the rotatable range of the body portion 24 is theoverlapping rotating range in which the optical imaging device 12 andthe electron beam imaging device 11 overlap each other. For example, inthe case of the rotatable range of 150° of the body portion 24 and theoffset angle of 40°, the overlapping rotating range becomes150°−40°=110°. Preferably, both the electron microscope image and theoptical image can be obtained at various tilt angles with increasingoverlapping rotating range. Ideally, the overlapping rotating range of0° to 180° covers the whole upper surface of the specimen stage 33. Inthis case, the electron microscope image and the optical image can beobtained at almost all tilt angles. However, because the rotation of theobservation device 10 is interrupted when the observation device 10projected from the body portion 24 comes into contact with the surfaceon which the magnifying observation apparatus is installed, there isphysical restriction by the length in which each observation device 10is projected from the body portion 24 and the height of the leg portion26 used to install the magnifying observation apparatus on the floorsurface. Therefore, the overlapping rotating range becomes about 60° toabout 180°. Preferably, the projection length of each observation device10 and the length of the leg portion 26 are set such that theoverlapping rotating range of 180° or the overlapping rotating rangeclose to 180° is implemented. Herein, the tilt angle is computedassuming that the tilt angle is set to 0° when the electron beam imagingdevice 11 is located in the vertical posture. For example, in theexample of FIG. 17B, the electron beam imaging device 11 has the totalrotatable range of 150°, namely, the rotatable range of 90° on the leftside from the vertical posture and the rotatable range of 60° on theright side from the vertical posture. Because the rotatable range of theoptical imaging device 12 is fixed while tilted by 40° on the right sidefrom the electron beam imaging device 11, the optical imaging device 12has the total rotatable range of 150°, namely, the rotatable range of50° on the left side from the vertical posture and the rotatable rangeof 100° on the right side from the vertical posture as illustrated inFIG. 17C.

As described above, in the observation devices 10 (optical imagingdevice 12 and electron beam imaging device 11), the distance to thespecimen located on the rotation axis can substantially be kept constantduring the rotational transfer (rotating). Therefore, once the focaldistance is adjusted, advantageously only the rotation angle, namely,the viewpoint can be changed in the in-focus state even if the positionis changed.

(Outline of Electron Beam Imaging Device 11)

An outline of the electron beam imaging device 11 will be described withreference to FIG. 18. FIG. 18 is a block diagram illustrating a systemconfiguration of the electron beam imaging device 11. In FIG. 18, theSEM in which the electrostatic type electrostatic lens is used isutilized. The SEM includes an electron lens system that emits theelectron beam of the accelerated electrons to cause the electron beam toreach a specimen SA, a specimen chamber 21 (chamber) in which thespecimen SA is disposed, an evacuation system that evacuates thespecimen chamber 21, and an operation system for the image observation.The electron beam imaging device 11 of FIG. 18 controls each memberusing an electron microscope controller 40 in order to observe theelectron microscope image that is the electron beam observation imageobtained by the charged particle beam. The electron beam imaging device11 also performs settings of image observation conditions and variousoperations of the electron microscope using an electron microscopeoperation program executed by the controller 1 of FIG. 18 and displaysthe observation image on the display section 2.

(Electron Lens System)

The electron lens system includes the electron gun 47 that emits anelectron beam EB of the accelerated electrons, an electron lens systemthat narrows an accelerated electron flux to form a fine beam, and adetector that detects secondary electrons and reflection electronsgenerated from the specimen SA. The electron beam imaging device 11 ofFIG. 18 includes the electron gun 47 that is the electron lens system toirradiate the specimen with the electron beam EB, a gun aligner 49 thatis the optical axis adjuster to correct the electron beam EB emittedfrom the electron gun 47 such that the electron beam EB passes throughthe center of the electron lens system, a condenser lens that is afocusing lens 52 to finely narrow a spot size of the electron beam EB,an electron beam deflecting and scanning section 58 that scans thespecimen SA with the electron beam EB focused by the focusing lens 52, asecondary electron detector 61 that detects the secondary electronsemitted from the specimen SA in association with the scanning, and areflection electron detector 62 that detects the reflection electrons.

(Evacuation System)

The specimen chamber 21 includes the specimen stage 33, a specimenintroducing device, and an X-ray detecting spectroscope. The specimenstage 33 (stage) is controlled by a specimen stage controller 34, andthe specimen stage 33 has a moving function in X-, Y-, and Z(height)-directions and a rotation (R) function. The four axes aremotor-driven, or part of or all the four axes can manually be driven.The evacuation system includes the decompression unit 15 describedabove.

(Operation System)

The operation system performs adjustment of an irradiation current andfocusing while displaying and observing the secondary electron image,the reflection electron image, the X-ray image, and the like. Generally,an output of the secondary electron image is film photographing with acamera for an analog signal. Recently, the image is outputted whileconverted into a digital signal, and various pieces of processing suchas data storage, image processing and printing can be performed. The SEMof FIG. 18 includes the display section 2 that displays the observationimages such as the secondary electron image and the reflection electronimage and a printer 69 for the printing. The operation system includes asetting guidance section that guides a sequence for setting itemsnecessary to set at least the acceleration voltage and the spot size(diameter of incident electron beam flux) as image observationconditions.

(Details of Electron Beam Imaging Device 11)

Next, the electron beam imaging device 11 will be described in detailwith reference to FIG. 18. The SEM of FIG. 18 is connected to thecontroller 1 and the display section, the electron beam imaging device11 is operated by the controller 1, the result is displayed on thedisplay section, and the image observation condition and the image dataare stored or the image processing and computation are performed ifneeded. A central processing portion 60 of FIG. 18 including a CPU andan LSI controls each block constituting the electron beam imaging device11. The central processing portion 60 controls an electron gunhigh-voltage power supply 43 to cause the electron gun 47, whichincludes a filament 44, a Wehnelt electrode 45, and an anode 46, to emitthe electron beam EB. The electron beam EB emitted from the electron gun47 does not always pass through the center of the electron lens system,and the gun aligner 49 is controlled by an optical axis adjuster 50 toperform the correction such that the electron beam EB passes through thecenter of the electron lens system. Then, the electron beam EB is finelynarrowed by the condenser lens that is the focusing lens 52 controlledby a focusing lens controller 51. The focused electron beam EB passesthrough an electron beam deflecting and scanning section 58, anobjective lens 59, and an objective diaphragm 53, which deflect theelectron beam EB, and an astigmatism corrector 57 that determines a beamspread angle of the electron beam EB, and the electron beam EB reachesthe specimen SA. The astigmatism corrector 57 that controls a scanningspeed or the like is controlled by an astigmatism corrector controller54. Similarly, the electron beam deflecting and scanning section 58 iscontrolled by an electron beam deflecting and scanning sectioncontroller 55, the objective lens 59 is controlled by an objective lenscontroller 56, and the specimen SA is scanned with the electron beam EBby the action of the electron beam deflecting and scanning section 58and the objective lens 59. Information signals such as the secondaryelectrons and the reflection electrons are emitted from the specimen SAby scanning the specimen SA with the electron beam EB, and theinformation signals are detected by the secondary electron detector 61and the reflection electron detector 62. An A/D converter 65 performsA/D conversion to the information signals of the detected secondaryelectrons through a secondary electron detecting and amplifying portion63. The information signals of the reflection electrons are detected bythe reflection electron detector 62, and an A/D converter 66 performsA/D conversion to the information signals of the reflection electronsthrough a reflection electron detecting and amplifying portion 64. Then,the information signals of the detected secondary electrons and theinformation signals of the reflection electrons are transmitted to animage data generator 67 to form image data which is retained in a firststorage section 131. The image data retained by the first storagesection 131 is transmitted to the controller 1 and displayed on thedisplay section 2 such as a monitor which is connected to the controller1, and the image data is printed by a printer 69 if needed. Anevacuation system pump 70 evacuates the specimen chamber 21. Anevacuation controller 72 connected to the evacuation system pump 70adjusts the vacuum, and the evacuation controller 72 controls the vacuumfrom the high vacuum to the low vacuum according to the specimen SA andthe observation purpose.

(Electron Gun 47)

The electron gun 47 is a source that generates the accelerated electronhaving a certain level of energy. Examples of the electron gun 47include a thermal electron gun that heats a W (tungsten) filament or aLaB₆ filament to emit electrons and a field emission electron gun thatapplies a strong electric field to a pointed tip of W to emit electrons.On the other hand, the electron lens system is controlled by an electronmicroscope magnifying power adjusting section 68 to adjust the electronmicroscope magnifying power. The focusing lens 52, the objective lens59, the objective diaphragm 53, the electron beam deflecting andscanning section 58, the astigmatism corrector 57, and the like aremounted on the electron lens system. The focusing lens more finelynarrows the electron beam EB emitted from the electron gun 47. Theobjective lens 59 finally focuses an electron probe onto the specimenSA. The objective diaphragm 53 is used to reduce an aberration. Thedetector includes the secondary electron detector 61 that detects thesecondary electrons and the reflection electron detector 62 that detectsthe reflection electrons. Because of low energy, the secondary electronsare captured by a collector, converted into photoelectrons by ascintillator, and signal-amplified by a photomultiplier. On the otherhand, the reflection electrons are detected by the scintillator or asemiconductor detector. The invention is not limited to the secondaryelectron signal detection and the reflection electron signal detection,but signal detectors for Auger electrons, transmission electrons, aninternal electromotive force, cathode luminescence, an X-ray, andabsorption electrons can be applied to the present invention.Alternatively, the reflection electron detector may be eliminated.

(Electron Lens System)

(Electrostatic Lens)

In the SEM that is the electron beam imaging device 11, theelectrostatic lens that is the electrostatic type electron lens is usedas the electron lens. Because the electrostatic type SEM is light inweight, the electrostatic type SEM is suitable to the structure of thepresent embodiment in which the electron beam imaging device 11 istilted. FIG. 19 is a block diagram illustrating an outline of theelectrostatic lens. As illustrated in FIG. 19, the electrostatic lenshas the structure in which each electron lens in the electron lensbarrel is electrically controlled by an electrostatic lens controller40A. The electron lens barrel includes an electron gun 47A, a firstcondenser lens 52A, a second condenser lens 57A, an electron beamdeflecting and scanning section 58, a scanning electrode 58A that scansthe specimen with an electron beam EB1, and an objective lens 59A. Theelectron gun 47A includes a filament 44A that is an electron beamsource, a Wehnelt electrode 45A that is the electron beam focusingcylindrical electrode, and an anode 46A. The electrostatic lenscontroller 40A includes an electron gun high-voltage power supply 43Athat controls the filament 44A and the Wehnelt electrode 45A to causethe electron gun 47A to emit the electron beam EB1, a first lenscontroller 51A that controls the first condenser lens 52A, a second lenscontroller 54A that controls the second condenser lens 57A, a scanningelectrode controller 55A that controls the scanning electrode 58A, andan objective lens controller 56A that controls the objective lens 59A.In the electrostatic lens, the plurality of electrodes are combined, thespecimen SA is irradiated with the electron beam EB1 by utilizingfocusing action of the positive electric field on the electron beam EB1,and a secondary electron SE1 emitted from the specimen SA is detected bya secondary electron detector 61A. Although the electron lens havingsuch a structure has the large aberration, advantageously the structurecan be simplified to reduce the weight of the electron beam imagingdevice 11, and therefore the observation device 10 can stably be rotatedto improve reliability. In the example of FIG. 19, the electron beamdeflecting and scanning section 58 includes one-stage scanning electrode58A. Alternatively, the electron beam deflecting and scanning section 58may include a plural-stage scanning electrode.

(Electromagnetic Lens)

The present invention is not limited to the electrostatic lens of theelectron beam imaging device 11, and another electron lens may be usedas appropriate. For example, an electromagnetic lens that is a magneticfield type electron lens may be used as the electron lens as long as themechanical strength can sufficiently be maintained. Advantageously, theelectromagnetic lens is suitable to the high magnifying power. FIG. 20illustrates an outline of the electromagnetic lens. The electromagneticlens of FIG. 20 has the structure in which the each electron lens in theelectron lens barrel is electrically controlled by an electromagneticlens controller 40B. The electron lens barrel includes an electron gun47B, a first condenser lens 52B, a second condenser lens 57B, a scanningcoil 58B that scans the specimen with an electron beam EB2, and anobjective lens 59B. The electron gun 47B includes a filament 44B that isthe electron beam source, a Wehnelt electrode 45B that is the electronbeam focusing cylindrical electrode, and an anode 46B. Theelectromagnetic lens controller 40B includes an electron gunhigh-voltage power supply 43B that controls the filament 44B and theWehnelt electrode 45B to cause the electron gun 47B to emit the electronbeam EB2, a first lens controller 51B that controls the first condenserlens 52B, a second lens controller 54B that controls the secondcondenser lens 57B, a scanning coil controller 55B that controls thescanning coil 58B, and an objective lens controller 56B that controlsthe objective lens 59B. In the electromagnetic lens, the specimen SA2 isirradiated with the electron beam EB2, and a secondary electron SE2emitted from the specimen SA2 is detected by a secondary electrondetector 61B. The above-described electrostatic lens utilizes theelectric field while the electromagnetic lens utilizes the magneticfield of the electromagnet to irradiate the specimen SA2 with theelectron beam EB2.

The electromagnetic lens in which the electromagnet is used is generallyutilized in the magnetic field type electron lens. Alternatively, byusing not the electromagnet but a permanent magnet as a magnetic fieldgenerating section, the simplification, miniaturization, and weightreduction of the lens structure can be achieved. However, in such cases,the focal distance becomes a fixed value because the magnetic fieldcannot be adjusted unlike the electromagnet. For the sake ofconvenience, the electromagnetic lens in which the permanent magnet isused is also referred to herein as the electromagnetic lens.

(Detector)

In the example of FIG. 3, the secondary electron detector (SED) 61 isused as the detector. As described above, another detector can be usedinstead of or in addition to the secondary electron detector 61. In theexample of FIG. 3, the secondary electron detector 61 is provided in thefixed part. Preferably, the secondary electron detector 61 is providedin the end-face plate located on the back surface side. Because both thespecimen stage 33 and the secondary electron detector 61 are located inthe fixed part, the positional relationship between the specimen stage33 and the secondary electron detector 61 is invariable, and thesecondary electron can stably be detected. Particularly, in the tiltobservation in which the specimen stage is tilted, advantageously thesecondary electron does not become a shadow of the specimen stage, butthe secondary electron can securely be captured. That is, in theconventional configuration in which the specimen stage side is tiltedwhile the electron gun and the secondary electron detector are fixed,sometimes the specimen surface becomes a shadow of the specimen stagewhen viewed from the secondary electron detector, which results in aproblem in that detection sensitivity of the secondary electron isdegraded. On the other hand, in the above configuration in which thespecimen stage side is fixed while the electron gun side is tilted,because the specimen stage is not tilted even in the tilt observation,such a shadow problem is not generated. As a result, advantageously thestable observation result can be obtained even in the tilt observation.However, the present invention is not limited to such a configuration.For example, the detector may be provided on the rotation part side.

(Specimen Stage 33)

As illustrated in FIGS. 6 to 8, the specimen stage 33 is disposed in thespecimen chamber 21 in order to place the observation target specimen.The specimen stage 33 is a circular table having the flat upper surface.FIGS. 6 to 8 illustrate the specimen stage 33 broken away in asemicircle for the purpose of explanation. The specimen stage 33 isdisposed in the position that is substantially aligned with the centeraxis of the cylindrical specimen chamber 21. Strictly speaking, sincethe specimen stage 33 can vertically be elevated and lowered whilemaintained in the horizontal posture, the moving mechanism is adjustedsuch that the specimen placement surface of the specimen stage 33 ismatched with an intersection of the optical axes of the two observationdevices 10.

The specimen is disposed in the substantial center of the rotation axis,and the specimen is observed while each observation device 10 isretained while oriented toward the center axis. Therefore, even if eachobservation device 10 is rotated along the rotation axis, the opticalaxis is always oriented toward the specimen, and the specimen can becaptured in the visual field. Additionally, once the focal distance(working distance (WD)) is adjusted, the constant working distance isalways maintained even if the observation device 10 is rotated, so thatthe observation can be performed from different angles while the focusedstate is substantially maintained. That is, because a visual field losscaused by the movement of the observation device 10 can extremely bereduced, advantageously a beginner user who is not used to the operationcan easily perform the operation.

(Specimen Stage Driving Section 34)

The observation position is determined by physically moving the specimenstage 33 on which the specimen SA is placed. The specimen SA is moved bythe horizontal surface moving mechanism 74 and the height adjustingmechanism 80, which constitute the specimen stage driving section 34that drives the specimen stage 33. The specimen stage driving section 34is controlled by the specimen stage controller 34. The specimen stage 33can be moved and adjusted in various directions such that theobservation position of the specimen SA can be adjusted. Specifically,the horizontal surface moving mechanism 74 is provided in order to movethe specimen stage 33 in the horizontal plane. The horizontal surfacemoving mechanism 74 can perform the movement and the fine adjustment inthe X-axis and Y-axis directions that are the planar direction of thespecimen stage 33. An R-axis (rotation) direction may be added to thehorizontal surface moving mechanism 74. The specimen stage drivingsection 34 acts as an observation positioning section that determinesthe observation position with respect to the specimen.

(Horizontal Surface Moving Mechanism 74)

As illustrated in FIGS. 6 to 7, in the horizontal surface movingmechanism 74, an X-axis operation knob 74X, a Y-axis operation knob 74Y,and an R-axis operation knob 74R are provided on the right side of thebody portion 24 so as to be projected frontward. The X-axis operationknob 74X, the Y-axis operation knob 74Y, and the R-axis operation knob74R manually adjust the moving amounts of the specimen stage 33 in theX-axis direction, the Y-axis direction, and the R-direction. Asillustrated in FIGS. 6 to 7, in the movement of the specimen stage 33 inthe X-axis direction, the Y-axis direction, and the R-axis direction, atorque is transmitted according to a rotation amount of each operationknob by a caterpillar belt drive tensioned at a rear end of eachoperation knob and gear drive, thereby moving the specimen stage 33 by apredetermined amount.

(Operation Knob)

In the height adjusting mechanism 80, a Z-axis operation knob 80Z thatadjusts the moving amount of the specimen stage 33 in the Z-axisdirection is provided so as to be projected upward from the back surfaceof the fixing plate 23. The operation knobs are unified to a rotationtype, which allows the user to adjust the movement of the specimen stage33 with a unified operation feeling. In the examples of FIGS. 6 and 7,the X-axis operation knob 74X, the Y-axis operation knob 74Y, and theR-axis operation knob 74R are provided on the right side of the bodyportion 24 while projected from the vertical surface. However, thepresent invention is not limited to such disposition and position, andthe X-axis operation knob 74X, the Y-axis operation knob 74Y, and theR-axis operation knob 74R may be provided in an arbitrary position andan arbitrary disposition of the magnifying observation apparatus. Forexample, in the magnifying observation apparatus of the modificationsillustrated in FIGS. 2B and 2C, the X-axis operation knob 74X, theY-axis operation knob 74Y, and the R-axis operation knob 74R are arrayedin the horizontal plane. A projection that is held by fingers tofacilitate the continuous rotation during the rotation may be providedin each operation knob. Further, the Z-axis operation knob 80Z is fixedsuch that the rotation axis is projected from the side surface while theknob part becomes the vertical posture, which allows the user tosensuously recognize the adjustment in the height direction from theposture of the knob to easily distinguish the Z-axis operation knob 80Zfrom another knob.

(Non-Tilt)

In the specimen stage 33, the movement can be performed only in thehorizontal plane, while the tilt angle (T-axis direction) adjustmentthat can be performed in the conventional specimen stage is eliminated.In other words, the specimen stage driving section 34 does not include atilt section that tilts the specimen stage 33. The specimen stage 33 isfixed to the horizontal posture in the non-tilted state in which thetilt action of the specimen stage 33 is prohibited, so that the specimenplaced on the upper surface of the specimen stage 33 can prevented frombeing moved or sliding down due to the tilt. Advantageously, theconventionally-required work that fixes the specimen to the specimenstage using a double-sided adhesive tape is eliminated, and the breakageof the specimen caused by the adhesion and peel-off of the adhesive canalso be avoided.

The observation device side is tiled, namely, rotated instead of tiltingthe specimen stage 33, whereby advantageously the user can easilyrecognize the change of the visual field in the tilt observation.Conventionally, because the observation device side such as the electrongun is fixed while the specimen side is tilted, the change of the visualfield emerges as the change of the observation target, and it isdifficult for the user to recognize which posture the specimen is in,which direction the specimen is viewed from, and which axis is to beadjusted in which direction in order to obtain the desired visual field.Therefore, it has been necessary for a skillful person to perform thefine adjustment. On the other hand, in the configuration in which thespecimen is fixed while the observation device side is moved (rotated),the user physically tilts the observation device by hand, and theposition of the specimen is fixed, so that the user can easily recognizethe positional relationship between the specimen and the observationdevice side. In other words, similarly to the general observation, theconfiguration is close to the action in which the viewpoint of the useris moved with respect to the fixed specimen, the relative positionalrelationship becomes extremely clear in addition to the manualadjustment of the observation device by the user. Since the relativeposition between the specimen and the observation device can also berecognized in changing the visual field, the user can easily understandthat the desired visual field is adjusted by moving which axis in whichdirection, and even the user who is not used to the specimen stagedriving section 34 can intuitively recognize the operation.

(Height Adjusting Mechanism 80)

In the specimen stage 33, the height adjusting mechanism 80 that adjuststhe horizontal position can adjust the Z-axis direction that is thevertical direction in order to adjust the distance (working distance)between the objective lens 59 and the specimen. The focal point variableranges of the electron beam imaging device 11 and the optical imagingdevice 12 are included in the moving locus of the height adjustingmechanism 80, which allows the focal point adjustments of the electronbeam imaging device 11 and the optical imaging device 12. In this case,the height adjusting mechanism 80 can be shared by the microscopic focusadjusting section 37 that adjusts the focal distance of the electronbeam imaging device 11 and the optical focus adjusting section 38 thatadjusts the focal distance of the optical imaging device 12. When eachobservation device 10 includes the focus adjusting section, the heightadjusting mechanism 80 can be used in conjunction with the focusadjusting section. When one of the observation devices 10 is a focalpoint fixed type including no focus adjusting section, the heightadjusting mechanism 80 acts as the focus adjusting section. For example,when the electron beam imaging device 11 includes the microscopic focusadjusting section 37 while the optical imaging device 12 is the focalpoint fixed type, the height adjusting mechanism 80 can be used as theoptical focus adjusting section 38.

The positioning of the observation image and the movement of theobservation visual field are not limited to the method of physicallymoving the specimen stage. For example, a method (image shift) ofshifting the scanning position of the electron beam emitted from theelectron gun may be used. Alternatively, the virtual movement may beused in conjunction with the physical movement. Alternatively, a methodof capturing the image data once in a wide range to process the imagedata in a software manner may also be used. In this method, because thedata is captured once and processed, the observation position can bemoved in the software manner, and the hardware movement such as thespecimen stage movement and the electron beam scanning is not performed.As to the method of previously capturing the large image data, there isa method of obtaining a plurality of pieces of image data in variouspositions and combining the pieces of image data to obtain the wide-areaimage data. Alternatively, the area can widely be obtained by obtainingthe image data at the low magnifying power.

(Optical Imaging Device 12)

The optical imaging device 12 will be described below. FIG. 21Aillustrates a configuration example of the optical lens system of theoptical imaging device 12. The optical lens includes an optical imagingelement 92 that is disposed in the optical lens barrel and an opticalzoom lens 93 and an objective lens 94, which constitute an optical lensgroup 98. Each lens includes a plurality of optical lenses. The opticalzoom lens 93 is driven in the manual or motor-driven manner to adjust agap between the lenses, thereby adjusting the magnifying power. For themotor drive, a motor is provided to move the position of the opticalzoom lens 93, and an optical zoom magnifying power is adjusted by therotation of the motor. The optical imaging device 12 includes an opticalmagnifying power adjusting section 95 in order to adjust the opticalmagnifying power. For the variable focal position, the optical focusadjusting section 38 may be provided in order to adjust the focalposition. For the fixed focal position, the optical focus adjustingsection can be eliminated. An illumination portion 96 is disposed inorder to illuminate a specimen SA3 placed on the specimen stage 33.

A CCD, a CMOS, and the like can be used as the optical imaging element92. In the optical imaging element 92, the reflected light or thetransmitted light of the light incident to the specimen SA3 through theoptical system is electrically read as an imaging signal in each oftwo-dimensionally arrayed pixels to form an optical image. The imagedata electrically read by the optical imaging element 92 is transmittedto and processed by an information processing section 101.

(Optical Imaging System)

In the configuration of the magnifying observation system 1000illustrated in FIG. 1, the controllers are provided to control theoptical imaging device 12 and the electron beam imaging device 11,respectively. Herein, the electron microscope image device is controlledby the controller 1, and the optical imaging device 12 is controlled bythe information processing section 101 incorporated in the displaysection. In the present embodiment, the controller 1 is configured toperform the image processing such as image synthesis. Instead of theconfiguration in which the controller separately controls theobservation device, the plurality of observation devices may becontrolled by one controller. The use of the common controller canreduce the number of necessary members, and the user can operate onecontroller to control the plurality of observation devices. In theoperation of the observation devices, the operability is improved byproviding the unified environment and user interface.

FIG. 21B is a block diagram illustrating an optical imaging system inwhich the optical imaging device 12 is controlled by the informationprocessing section 101 of the display section 2. The optical imagingdevice 12 illustrated in FIG. 21B includes a light-receiving element,such as the CCD, as the optical imaging element that obtains the imageof the specimen SA3, a CCD control circuit 91 that drives and controlsthe CCD, and the optical lens group 98 that forms an image of thetransmitted light or reflected light of the light, with which thespecimen SA3 placed on the specimen stage 33 is illuminated from theillumination portion 96, on the CCD. The configuration illustrated inFIG. 21A can be utilized in the optical lens group 98. As described inFIG. 4 and the like, the horizontal surface moving mechanism 74 and theheight adjusting mechanism 80 are provided as the specimen stage drivingsection 34 that drives the specimen stage 33 on which the specimen SA3is placed. A mechanism that moves the optical lens group 98 in theoptical axis direction may be provided as the optical focus adjustingsection, or the height adjusting mechanism may also be used as theoptical focus adjusting section that changes the relative distance inthe optical axis direction to adjust the focal point.

On the other hand, the display section 2 includes a second storagesection 103 (corresponding to a second storage section 132 of FIG. 37),a display portion 102, an operation section 105 (corresponding tooperation section 105 c of FIG. 37), an information processing section101, and an interface 104. The second storage section 103 such as amemory stores image data electrically read by an imaging element. Thedisplay portion 102 displays the image based on the image dataelectrically read by the imaging element. The operation section 105performs an operation such as input based on the screen displayed on thedisplay portion 102. The information processing section 101 performsvarious pieces of processing such as image processing based oninformation inputted from the operation section 105. The informationprocessing section 101 transmits and receives information to and fromthe optical imaging device 12 through the interface 104. The displayportion 102 is a monitor that can perform high-resolution display, andthe CRT or the liquid crystal panel is used as the display portion 102.

In the second storage section 103, for example, focal distanceinformation on the relative distance in the optical axis directionbetween the specimen stage 33 and the optical lens group 98 in adjustingthe focal point with the optical focus adjusting section is stored alongwith two-dimensional position information on the specimen SA3 in a planesubstantially perpendicular to the optical axis direction. When anarbitrary point or region is set on the image displayed on the displayportion 102 using the operation section 105, the information processingsection 101 computes the average height in the optical axis direction ofthe specimen SA3 corresponding to the set region based on the focaldistance information, stored in the second storage section 103, on partor whole of the specimen SA3 corresponding the set region. In themagnifying observation apparatus, the imaging element electrically readsthe reflected light or transmitted light of the light incident throughthe optical lens group 98 to the specimen stage 33 on which the specimenSA3 is placed, and the average height or depth in the optical axisdirection of the specimen SA3 corresponding to the specified region canbe computed. The information processing section 101 can also act as animage synthesizing section 116 that synthesizes the electron microscopeimage and the optical image.

The operation section 105 is connected to the computer in the wired orwireless manner, or the operation section 105 is fixed to the computer.For example, the general operation section 105 includes various pointingdevices such as a mouse, a keyboard, a slide pad, a track point, atablet, a joystick, a console, a jog dial, a digitizer, a light pen, anumerical keypad, a touch pad, and accu-point. The operation section 105can be used to operate the magnifying observation apparatus andperipheral devices thereof in addition to the operation of themagnification observation operation program. The touch screen or thetouch panel is used in the display that displays an interface screen,and the user directly touches the screen to enable input or operation.Alternatively, sound input and other existing input sections may be usedor commonly used. In FIG. 21B, the operation section 105 includes thepointing device such as the mouse.

The computer 70 can be connected to the display section 2, and themagnification observation operation program can additionally beinstalled in the computer 70 to operate the magnifying observationapparatus from the computer 70. Alternately, the display section may beimplemented by the computer. In this case, the monitor connected to thecomputer acts as the display portion of the display section.

(Pixel Shifting Section 99)

The optical imaging device 12 includes a pixel shifting section 99 thatshifts the pixels to obtain a resolution higher than a resolutionpossessed by the CCD. In the pixel shift, the high resolution isachieved by synthesizing the image that is obtained while a subject isshifted by a half of pixel pitch and the pre-shift image. Examples ofthe typical image shift mechanism include a CCD drive method of movingthe imaging element, an LPF tilt method of tilting the LPF, and a lensmovement method of moving the lens. In FIG. 21B, there is provided anoptical path shift portion 14 that optically shifts an incident opticalpath of the reflected light or transmitted light incident to the CCDthrough the optical lens group 98 from the specimen SA3 mounted on thespecimen stage 33 in at least one direction at a distance smaller than agap between pixels of the CCD in the direction. The mechanism ortechnique of implementing the image shift is not limited to theabove-described configurations, but other well-known methods can be usedas appropriate.

The CCD can electrically read a light-receiving amount in each of thepixels two-dimensionally arrayed in the x-direction and the y-direction.The image of the specimen SA3 formed on the CCD is converted into theelectric signal by each pixel of the CCD according to thelight-receiving amount and further converted into the digital data bythe CCD control circuit 91. The information processing section 101stores the digital data converted by the CCD control circuit 91 as thelight receiving data in the second storage section 103 along with pixeldisposition information (x, y) that is two-dimensional positioninformation on the specimen SA3 in a plane (x- and y-directions in FIG.21B) substantially perpendicular to the optical axis direction(z-direction in FIG. 21B). Herein, the plane substantially perpendicularto the optical axis direction is not exactly a plane having a rightangle with respect to the optical axis, but an observation surfacelocated within a tilt range to a degree in which the shape of thespecimen can be recognized in the resolution of the optical system andthe imaging element.

As described above, in the configuration of the magnifying observationsystem 1000 of FIG. 1, the optical imaging device 12 is controlled bythe information processing section 101 incorporated in the displaysection 2 while the electron beam imaging device 11 is controlled by thecontroller. That is, the controller is separately provided in eachobservation device. The present invention is not limited to such aconfiguration, and one controller may control the plurality ofobservation devices.

(Illumination Portion 96)

In the illumination portion 96 illustrated in FIG. 21B, epi-illuminationthat illuminates the specimen SA3 with the light incident from theviewing direction is illustrated. The present invention is not limitedthereto, and transmission illumination that illuminates the specimen SA3with the transmitted light may also be used. The illumination portion 96is connected to the display section 2 through an optical fiber 106. Thedisplay section 2 includes a connector that connects the optical fiber106, and the display section 2 incorporates a light source 107 thatoutputs the light to the optical fiber 106 through the connectortherein. A halogen lamp, a xenon lamp, the LED, or the like is used asthe light source 107.

As illustrated in FIGS. 4 and 7, the illumination portion 96 is disposedat a light source port 97 in the specimen chamber 21. In theillumination portion 96 connected to the light source port 97, theoptical axis of the illumination light is set such that the illuminationlight is oriented toward the specimen stage 33. Preferably, asillustrated in FIG. 4, the illumination portion 96 is located on a planedifferent from the rotation plane in which each observation device 10 isprovided, and the optical axis is set at an angle intersecting therotation plane. By tilting the illumination light in this manner, thedirection in which the shadow is generated in the specimen by theillumination light does not become in parallel with the rotation planebut intersects the rotation plane, so that the dark shadow part caneffectively be reduced in the tilt observation.

Preferably, the inner surface of the specimen chamber 21 hasreflectiveness. Therefore, the illumination light is reflected in thespecimen chamber 21 as much as possible, and effectively a shade of theillumination can be decreased by irregular reflection. For example, theinner surface of the specimen chamber 21 is coated with ahigh-reflectance metal such as Ag coat.

The light source port 97 is provided on the rotation part side.Therefore, because the illumination portion 96 is also rotated alongwith the rotating of the body portion 24, the positional relationshipbetween the optical imaging device 12 and the illumination portion 96can be kept constant, and the specimen is continuously illuminated atthe same angle in the radial direction irrespective of the position ofthe optical imaging device 12. As a result, advantageously theillumination state does not change according to the rotating of theoptical imaging device 12.

(In-Specimen-Chamber Observation Device 13)

In the present embodiment, an in-specimen-chamber observation device 13is provided as a third observation device in order to observe anenvironment in the specimen chamber 21. The in-specimen-chamberobservation device 13 that is the additional optical imaging device canobtain an optical image as an in-specimen-chamber image. The opticalimage includes at least the specimen stage 33, the specimen placed onthe specimen stage 33, and the leading end portion of the electron beamimaging device 11 in the visual field. Therefore, the specimen in thespecimen chamber 21, and the positional relationship between the opticalimaging device 12 and the electron beam imaging device 11 can easily berecognized. Particularly the position in which specimen is placed isadvantageously confirmed. For example, in the configuration in which thespecimen stage 33 is pulled out frontward from the specimen chamber 21,although the specimen placement work is easy to perform, it cannot bepreviously confirmed how the specimen is viewed by the observationdevice according to the specimen placement position. On the other hand,by providing the in-specimen-chamber observation device 13, the user canplace the specimen in the desired position on the specimen stage 33before the evacuation while confirming the in-specimen-chamber imagethat is the optical image of the in-specimen-chamber observation device13 in real time. That is, advantageously the specimen can be placedwhile confirming the specimen placement position. Thein-specimen-chamber observation device 13 may include the imagingelement such as the CCD and the CMOS, and is also referred to as aChamber View Camera (CVC).

Preferably, the optical axis of the in-specimen-chamber observationdevice 13 is substantially parallel to the rotation axis. Therefore, therotational transfer of the body portion 24 can be recognized from above,and the rotation state can easily be recognized as the arc locus. Therotation axis can be included in the optical image by an offsetdisposition in which the optical axis is offset so as to become parallelto the rotation axis, so that the rotation can more easily berecognized. Preferably, an offset amount of the optical axis of thein-specimen-chamber observation device 13 is set in a range of about±10% of the cylindrical radius based on the rotation axis of the bodyportion 24. As used herein, that “the specimen stage 33 is substantiallythe same to a height of the rotation axis” is used in the sense ofincluding the offset position. Herein, “parallel” is used in the senseof including the angle difference up to about 20° with respect to therotation axis. When the in-specimen-chamber observation device 13 isdisposed at the offset position in the specimen chamber, more preferablythe optical axis of the in-specimen-chamber observation device 13 islocated above the rotation axis. Therefore, the specimen observationsurface aligned with the rotation axis can be included in the lowerportion of the in-specimen-chamber image, and the positionalrelationship between the specimen and the electron gun can securely berecognized.

When the electron beam imaging device 11 is rotated along with the bodyportion 24, the position in which the in-specimen-chamber observationdevice 13 is fixed is desirably located on the fixed part side that doesnot rotate, because the electron beam imaging device 11 and the bodyportion 24 are rotated while the presence or absence or a risk of theinterference between the specimen stage 33 and the specimen placed onthe specimen stage 33 is confirmed.

However, the in-specimen-chamber observation device 13 can also beprovided on the rotation part side. In this case, rotation angleinformation on the body portion 24 is obtained by the angle sensor orthe like to control the correction of the image rotation, which allowsthe acquisition of the still image in which the rotation motion iscancelled. For example, the controller 1 computes a rotation amount ofthe rotating portion and the moving amount of the visual field, and theimage processing is performed such that the display part of theobservation visual field is moved in the reverse direction by the movingamount of the visual field. Therefore, the in-specimen-chamber image isdisplayed as the rotation correction image in which the correction isperformed so as to cancel the tilt caused by the rotation of the bodyportion, so that the visual field of the image displayed on the displaysection 2 can be kept constant irrespective of the rotation position.

FIGS. 22A and 22B are schematic sectional views illustrating relativemovement between the specimen stage 33 and the observation device 10 inthe specimen chamber 21. As described above, only the specimen stage 33is vertically moved by the height adjusting mechanism 80 whilemaintained in the horizontal posture, and the tilt and oscillation, inwhich the specimen placement surface of the specimen stage 33 isinclined, are prohibited in the specimen stage 33. In order to implementthe tilt observation with this configuration, the specimen stage 33 isconfigured to tilt the side of the observation device 10. When thespecimen side is fixed while the side of the observation device 10 istilted, advantageously the user can easily recognize the positionalrelationship of the tilt posture in the observation image that isobtained by the observation device 10 and displayed on the displaysection 2. Conversely, in the conventional structure in which the cameraside is fixed while the specimen stage 33 is tilted, namely, in aeucentric structure illustrated in FIGS. 23A and 23B, when the tiltangle of the tilt observation is changed in the currently observedimage, it is difficult to recognize the positional relationship as towhich direction the tilt should be adjusted to obtain the desired image.On the other hand, in the configuration of the present embodiment inwhich the specimen side that is the observation target is fixed whilethe side of the observation device 10 that becomes the viewpoint of theobservation, namely, an eye line is moved, advantageously the positionalrelationship can be recognized with a sense of moving the eye line,similar to when the user actually observes the object, and therefore thedirection in which the angle should be adjusted can quickly berecognized.

Because the specimen stage 33 is not tilted, a risk that the specimenslides down from the specimen stage 33 is eliminated, the structure tofix the specimen to the specimen stage 33 and the work to fix thespecimen with the adhesive tape are eliminated, and a risk of breakingthe specimen is eliminated in peeling of the adhesive tape. Therefore,workability and safeness are improved.

In the conventional eucentric structure, when the height (Z-axis) of thespecimen stage 33 is changed while the specimen stage 33 is tilted, thespecimen stage 33 is moved from the black position illustrated in FIG.23B to the hatching position, and the optical axis of the opticalimaging device 12 fixed in the tilt posture is relatively moved on thespecimen stage 33, which results in a problem in that the observationvisual field is unintentionally moved. Particularly, in the focal pointfixed type in which the optical imaging device 12 does not include theoptical focus adjusting section that adjusts the focal position, it isnecessary that the working distance be changed only by adjusting theheight of the specimen stage 33, and the observation visual field maynot be matched with that of the electron microscope depending on thefocused position.

When the angle between the observation device 10 and the specimen ischanged, it is necessary to correct the focal position since the focaldistance between the observation device 10 and the specimen varies everytime the angle is changed. Additionally, in obtaining the tiltobservation images of the same specimen at the same tilt angle by thetwo observation devices 10, it is necessary to store the angle used inone of the observation devices 10, and it is necessary to reproduce thisangle to adjust the focal position after the specimen stage 33 is movedonto the side of the other observation device 10.

On the other hand, in the present embodiment, as illustrated in FIGS.22A and 22B, the observation visual field can be kept constantirrespective of the height of the specimen stage 33 by performing therotational transfer of the observation device 10 to the verticalposition. In the present embodiment, the observation device 10 to beused is located in the vertical posture, namely, the optical axis of theselected observation device 10 is substantially aligned with the movingdirection (Z-axis) of the height adjusting section. Therefore, themovement of the observation visual field caused by the height adjustmentcan be avoided. As a result, the eucentric working distance becomes onlyone point. When the observation is performed while the observationdevice 10 is located in the vertical posture, the optical axis of theobservation device 10 is aligned with the axis of the vertical movementof the specimen stage 33, and the visual field is not moved even if theworking distance is adjusted. Therefore, advantageously the eucentricposition can easily be adjusted.

Obviously, the specimen can be observed even if the observation device10 is located in the tilt posture. In this case, although theobservation visual field is moved by the height adjustment of thespecimen stage 33, the movement of the observation visual field can becancelled through the image processing. For example, the controller 1computes the change in height and the moving amount of the visual field,and the controller 1 performs the image processing such that the displaypart of the observation visual field (the optical image and the electronmicroscope image on the display) is moved in the reverse direction bythe movement of the visual field. Therefore, the visual field of theimage displayed on the display section 2 can be kept constantirrespective of the change in height. As a result, there can beimplemented the magnifying observation apparatus in which theobservation visual field does not change irrespective of the angle andthe observation position of the specimen stage 33 even if theobservation device 10 is switched.

Particularly, in the conventional design concept, the observation withthe optical imaging device 12 is sacrificed due to a high priority tothe electron microscope observation, and the tilt observation isrestricted due to a high priority to the resolution (maximum magnifyingpower) of the electron microscope. As a result, although both theelectron beam imaging device 11 and the optical imaging device 12 areprovided, the user cannot take advantage of the electron beam imagingdevice 11 and the optical imaging device 12 to a maximum extent toutilize the optical image and the tilt observation without limitation.

Specifically, the resolution of the electron microscope becomes betterwith decreasing working distance that is the distance to the specimenfrom the leading end of the objective lens of the electron beam imagingdevice 11. However, when the specimen is observed from the tilted angle,unfortunately the specimen comes into contact with the objective lens ofthe electron beam imaging device 11 when the working distance is tooshort. Conventionally, the observation is performed while the workingdistance is set to the minimum distance in which the specimen does notcollide with the objective lens. The minimum distance is determined by asize of the specimen and the desired tilt angle. As a result, in theconventional electron microscope, the observation is performed at theworking distance that is determined by the size of the specimen and thedesired tilt angle. In order to comfortably perform the observation atvarious working distances, it is desirable that the observation visualfield does not change at any working distance when the tilt angle of thespecimen stage 33 changes. Therefore, in the conventional electronmicroscope, there is adopted the configuration in which the visual fieldis not moved at any working distance even if the specimen stage 33 istilted, namely, the tilt mechanism of the eucentric type specimen stage33 in which, as illustrated in FIG. 23B, the visual field is not shiftedirrespective of the position of the Z-axis of the specimen stage 33 onthe optical axis of the electron microscope.

According to this configuration, the adjustment is previously performedsuch that the specimen surface is located at the black position of FIGS.23A and 23B, which allows the observation to be performed in the samevisual field at the same tilt angle with the optical imaging device 12and the electron beam imaging device 11 only by one action to performthe tilted rotation of the specimen stage 33. However, it is necessarythat the optical imaging device 12 having a shallow depth of fieldperform the visual field search and the position adjustment, and thevisual field is shifted between the electron beam imaging device 11 andthe optical imaging device 12 in performing the position adjustment,which results in a problem in that the adjustment is hard to perform.

In view of the above circumstances, as described above in the presentembodiment, the side of the specimen stage 33 is fixed while the side ofthe observation device 10 is tilted as illustrated in FIGS. 22A and 22B.As a result, since not the specimen stage 33 but the side of theobservation device 10 is tilted, the images can easily be switched inthe same observation position at the same tilt angle irrespective of theheight of the specimen stage 33. Therefore, both the electron microscopeobservation and the optical microscope observation are emphasized, andthe tilt observation is also emphasized, which allows the implementationof the convenient magnification observation.

In the conventional electron microscope, the Z-stage as the heightadjusting mechanism 80 is provided in the member on which the electronlens and the optical lens are mounted, and the mechanism that tilts androtates the specimen stage 33 is provided on the Z-stage. The electronlens and the optical lens are mounted on the fixed part side.

On the other hand, in the magnifying observation apparatus of thepresent embodiment, the mechanism that rotates the specimen stage 33 isprovided in the member on which the electron lens and the optical lensare mounted, and the height adjusting mechanism 80 is further mounted onthe member. That is, the rotation axis mechanism and the Z-axis movingmechanism are provided at the reverse positions compared with theconventional electron microscope. The electron lens and the optical lensare mounted on the rotation part side.

(Alignment of Moving Direction of Optical Axis and Specimen Stage 33)

In the magnifying observation apparatus of the present embodiment, therotational transfers of the electron beam imaging device 11 and theoptical imaging device 12 are performed by the rotating device 30, whichallows both the observation devices 10 to be disposed in one observationposition by switching. That is, the imaging can be performed while theoptical axes of both the observation devices 10 are aligned with eachother by the switching. On the other hand, the specimen stage 33 canvertically be moved by the height adjusting mechanism 80 whilemaintained in the horizontal posture. As a result, the optical axis canbe aligned with the moving direction of the specimen stage 33 bylocating the observation device 10 in the vertical posture.

Therefore, the tilt observation can be performed by the electron beamimaging device 11 and the optical imaging device 12, which are rotatedalong the cylindrical shaped outer surface, and the rotation axis isaligned with the height direction of the specimen stage 33, namely, theheight of the observation surface of the specimen placed on the specimenstage 33 to enable the observation without changing the visual field.The observation image can be obtained in the substantially same visualfield at the substantially same tilt angle and at the substantially samemagnifying power while the optical axes of the observation devices 10are aligned with each other, and the comparative observation of the twoobtained observation images can be performed.

(Rotation Axis in Focal Point Variable Range)

The height adjusting section is set such that the rotation axis of therotating device 30 is included in a height variable range in which theheight can be adjusted. Thus, the specimen stage 33 is located in thecenter of the rotation axis, and the distance from the observationdevice 10 in each position to the specimen stage 33 can be kept constanteven if the observation device 10 is rotated along the rotation axis.Therefore, once the focal distance is adjusted, the focused distance canbe maintained even if the observation device 10 is moved, the visualfield angle can always be changed in the focused state, and it isextremely advantageous to the tilt observation.

More accurately, as illustrated in a schematic sectional view in FIG. 24illustrating the setback, the specimen stage 33 is lowered from therotation axis by the specimen height such that the observation positionof the specimen surface, namely, the observation surface that is theupper surface of the specimen is the same to a height of the rotationaxis, which allows the achievement of the working distance retainingstate. Therefore, the height adjusting mechanism 80 can be lowered inthe desired range from the position in which the specimen stage 33 isthe same to a height of the rotation axis. This enables the specimenstage 33 to be lowered according to the height of the observationsurface to correctly align the observation surface with the rotationaxis.

Accordingly, in the movement of the specimen stage 33 in the Z-axisdirection, an upper end stroke position of the specimen stage 33 can beelevated up to the position including at least the rotation axis, andthe specimen stage 33 can be lowered to the position below at least therotation axis.

(Adjustment of Setback)

The optical lens having the depth of field shallower than that of theelectron lens is used in order to align the specimen surface with therotation axis. The optical lens mounting position is previously adjustedsuch that the focal position of the optical lens is the same to a heightof the rotation axis. The body portion 24 is rotated such that theoptical axis of the optical lens becomes perpendicular to the specimenplacement surface of the specimen stage 33, and the Z-axis position ofthe specimen stage 33 is adjusted such that the image of the opticallens is focused. At this time, because only the distance between theoptical lens and the specimen is changed while the visual field is notmoved, the adjustment is easy to perform. Then the focal pointadjustment of the electron lens is performed in the similar procedure.Therefore, regardless of how the body portion 24 is rotated and tilted,the visual fields of the electron microscope and the optical microscopeare not shifted.

(Presence or Absence of Focus Adjusting Section, Focal Point Fixed Type)

When the focal distance of the observation device 10 is the fixed type,the working distance can correctly be adjusted to the focal position byadjusting the height of the specimen stage 33 with this configuration.Alternatively, when the observation device 10 includes the focusadjusting section, the working distance is set such that the rotationaxis of the rotating device 30 is included in the focal distance rangethat can be adjusted by the focus adjusting section. For example, theelectron beam imaging device 11 often includes the microscopic focusadjusting section 37 that can adjust the focal distance along theoptical axis. In such cases, as illustrated in FIG. 25, the setting ispreviously performed such that the rotation axis is included in thefocal position variable range, and the focal position of the electronlens is matched with the rotation axis position by adjusting the focaldistance using the microscopic focus adjusting section 37. Similarly,when the optical imaging device 12 includes the optical focus adjustingsection 38 that can adjust the focal distance along the optical axis, asillustrated in FIG. 26, the setting is previously performed such thatthe rotation axis is included in the focal position variable range, andthe optical focus adjusting section 38 is adjusted such that the focalposition is matched with the rotation axis.

(Second Embodiment)

In the above example, the optical imaging device 12 and the electronbeam imaging device 11 are combined by way of example. The presentinvention can be applied to not only the configuration in which theoptical imaging device 12 and the electron beam imaging device 11 arecombined but also the configuration in which the optical imaging device12 and the electron beam imaging device 11 are added if needed. Forexample, as described above, the magnifying observation systemillustrated in the block diagram in FIG. 18 can be configured bydetachably mounting the optical imaging device 12 on the magnifyingobservation system with the mount 39 interposed therebetween. Thus, theoptical imaging device 12 can be added if needed while the magnifyingobservation system is used as the electron microscope. Therefore, theuseful magnifying observation system having excellent flexibility andextendibility in which options can be added and removed according to theobservation application can be constructed.

(Magnifying Power Conversion Function)

The magnifying observation apparatus further has a magnifying powerconversion function. In the magnifying power conversion function, whendifferent observation devices have different decision criteria ofmagnifying power, the different observation device is displayed at aunified magnifying power, or the magnifying power expressed by thedifferent decision criterion is automatically adjusted to the unifiedmagnifying power. When performing observation with the magnifyingobservation apparatus, how much magnification is necessary for theobservation is generally indicated by the magnifying power. However,because a definition of the magnifying power depends on the size of thedisplay range, the magnifying power often varies in each observationdevice. Generally, the magnifying power is defined and computed by thefollowing equation.Magnifying power=display range of observation image/observation visualfield range

In the above equation, the display range is a parameter determined bynot the user but a designer of the observation device. On the otherhand, as to the observation visual field range, the user arbitraryselects a desired visual field range in the settable visual field rangedetermined by performance of the observation device. A magnifying powerdetermining method will be described below with reference to FIGS. 27and 28. FIG. 27 illustrates the visual field range and the display rangeof the electron beam imaging device 11, and FIG. 28 illustrates thevisual field range and the display range of the optical imaging device12.

(Electron Microscope Magnifying Power)

For example, in the electron beam imaging device 11 constituting thescanning electron microscope, generally the display range means aphotograph PH size (for example, 124 mm×94 mm), as illustrated in FIG.27. The observation visual field range means an actual size of the rangewhere the specimen is scanned with the electron beam emitted from theelectron gun through the electron lens.

(Optical Magnifying Power)

On the other hand, in the structure of the optical imaging device 12such as the digital microscope, as illustrated in FIG. 28, the lightreflected from the specimen SA illuminated with the illumination lightforms an image on the optical imaging element such as the CCD and theCMOS through the optical lens. Generally, the display range of theoptical imaging device 12 becomes a monitor size (for example, 15-inchmonitor screen size) of the display portion 102. The monitor size variesbased on whether the display portion 102 is the LCD or the CRT. Theobservation visual field range becomes (effective imaging range ofoptical imaging element)/(optical magnifying power of optical lens). Theoptical magnifying power becomes a magnification factor with respect tothe size of the object.

There is no limitation to the magnifying power determining method. In aspecific example, not the whole but part of the image data obtained fromthe observation visual field range may be displayed in the displayrange. In such a method, when a blur or deformation is generated in theperiphery of the image, the image is displayed while the blur ordeformation is cut. Alternatively, although the resolution becomescoarse, the apparent magnifying power may be increased by a so-calleddigital zoom. In such cases, the magnifying power is increased.

On the other hand, the observation visual field range may be moved inthe horizontal and vertical directions or an XY-direction to obtainplurality of pieces of image data, and the pieces of image data may becoupled to display the wide visual field range in the display range. Forexample, the image having the magnifying power lower than the observableminimum magnifying power may be obtained, or the high-resolution imagemay be obtained so that the digital zoom may be performed to thehigh-resolution image later. In such cases, the magnifying power isdecreased.

As described above, when the observation images in the same observationvisual field range are obtained by at least two kinds of the observationdevices while the magnifying powers of the observation devices differfrom each other in the definition, inconveniently the desiredobservation images in the same observation visual field range cannot beobtained even if the images are obtained at the same “magnifying power”.That is, even if the magnification observation is performed in the samevisual field range, the magnifying observation apparatus in which theimage is displayed on the large screen has the high magnifying power,and the magnifying observation apparatus in which the image is displayedon the small screen has the low magnifying power. As a result, when onlythe magnifying power is used as a reference, the size actually displayedby the observation device is variable, and it is unsuitable to thecomparative observation.

Therefore, conventionally a method of previously observing the specimenwhose size is well known to perform calibration work that confirms themagnifying power definition of each observation device, a method inwhich, in consideration of the difference of the magnifying powerdefinition, the user manually computes the magnifying power at which thesame observation visual field range can be observed, and a method ofusing not the same magnifying observation apparatus but the differentelectron microscope and optical digital microscope are taken ascountermeasures. Unfortunately, a large amount of time and effort isrequired in any of the methods.

On the other hand, in the present embodiment, the unified magnifyingpower is defined in both the observation devices such that the samedisplay size is obtained in the same observation visual field range. Inother words, a value in which the same display range is divided by theobservation visual field range is defined as the magnifying power.Therefore, even in the different observation devices, the designerdefines the same display range to add the magnifying power conversionfunction, which allows the user to utilize the magnifying power definedin the same way. Therefore, when the magnifying power is set to one ofthe observation devices, the value that is converted into the magnifyingpower of the other observation device is displayed along with the setmagnifying power. Alternatively, the magnifying power display of theother observation device may be changed, and the magnifying power of theother observation device may be displayed while converted into themagnifying power of one of the observation devices, or the magnifyingpower of the other observation device and the value converted into themagnifying power of one of the observation devices may be displayedtogether.

In addition to the fact that the magnifying power converted by one ofthe observation devices is converted by the magnifying power conversionsection, the magnifying power reference can be converted into athird-reference magnifying power that is different from the magnifyingpowers of the observation devices. In this case, the optical image andthe electron microscope image are displayed while unified by thethird-reference magnifying power.

(Magnifying Power Conversion Function)

FIG. 29 is a block diagram illustrating the magnifying observationapparatus including the magnifying power conversion function. Themagnifying observation apparatus of FIG. 29 includes the optical imagingdevice 12, the electron beam imaging device 11, the controller 1, andthe display section 2, and an operation section 105B. The controller 1includes a computing portion such as an MPU, and the controller 1 actsas a magnifying power conversion section 111 that converts themagnifying power of one of the observation devices by following a basisdefined by the other observation device and a mode selecting section 110that selects an observation mode. In this example, the magnifyingobservation apparatus includes a comparative mode and a synthetic modeas the observation mode, and the observation mode is selected by themode selecting section 110. In the comparative mode, comparativeobservation of the electron microscope image and the optical image canbe performed by the display section 2. In the synthetic mode, asynthetic image in which the electron microscope image and the opticalimage are synthesized can be displayed. It is not always necessary toimplement the synthetic mode, but only the comparative mode may beimplemented. In this case, it is not always necessary to include themode selecting section that selects the observation mode.

The operation section 105B includes an input device, and the useroperates the operation section 105B to set the electron microscopemagnifying power. Therefore, the user can operate the electronmicroscope magnifying power adjusting section 68 that sets and adjuststhe electron microscope magnifying power. In the example of FIG. 29, theoperation section 105B is connected to the controller 1. Alternatively,the operation section 105B can be shared by the operation section 105 orthe console CS, which is connected to the display section 2.

(Magnifying Power Conversion Section 111)

The display portion 102 of the display section 2 acts as a convertedmagnifying power display section 123, a magnifying power range displaysection 126, a predetermined magnifying power display section 124, adetermination notifying section 125, a state display section 121, and anon-selection display section 122, to be described later. The convertedmagnifying power display section 123 obtains the magnifying power of theimage that is obtained by one of the observation devices and displayedon the display section, and the converted magnifying power displaysection 123 determines whether the other observation device can be setto the converted magnifying power converted by the magnifying powerconversion section. When the other observation device can be set to theconverted magnifying power, the converted magnifying power displaysection 123 displays the converted magnifying power on each displaysection. When the other observation device cannot be set to theconverted magnifying power, the converted magnifying power displaysection 123 displays the magnifying power closest to the convertedmagnifying power in the settable magnifying powers on each displaysection. The magnifying power range display section 126 converts anadjustable electron microscope magnifying power range of the electronmicroscope image and an adjustable optical magnifying power range of theoptical image into the magnifying powers having the same basis toone-dimensionally display the converted magnifying powers on the displaysection. The magnifying power range display section 126 can also exhibitan overlapping range of the optical microscope magnifying power rangeand the electron microscope magnifying power range. The predeterminedmagnifying power display section 124 displays the converted magnifyingpower at the same display size as the image obtained by one of theobservation devices in order to obtain the image with the otherobservation device. When the magnifying power of the other observationdevice cannot be set to the converted magnifying power converted by themagnifying power conversion section, the determination notifying section125 displays that the magnifying power of the other observation devicecannot be set to the converted magnifying power. The state displaysection 121 performs state display in order to distinguish betweenmoving image display and still image display.

(Optical Magnifying Power Adjusting Section 95)

The optical imaging device 12 of FIG. 29 includes an optical magnifyingpower adjusting section 95 and an optical magnifying power readingsection 112. The optical magnifying power adjusting section 95 isprovided into a ring shape so as to be rotatable in the side surface ofthe optical lens barrel, and the magnifying power is adjusted by arotation amount of the ring. In the example of FIG. 29, an image of theoptical lens barrel incorporating an optical zoom lens is illustrated,wherein the optical magnifying power adjusting section 95 is provided inan outer circumference of the optical lens barrel and the opticalmagnifying power reading section 112 is provided to read the setmagnifying power. The optical magnifying power reading section 112 iselectrically connected to the computing portion, and an output of theoptical magnifying power reading section 112 is transmitted to themagnifying power conversion section 111 of the computing portion.

With this configuration, the user adjusts the magnifying power of theelectron beam imaging device 11 through the operation section 105B, andthe user adjusts the optical magnifying power of the optical microscopethrough the optical magnifying power adjusting section 95. When the useroperates the optical magnifying power adjusting section 95 to adjust theoptical magnifying power, the optical magnifying power reading section112 reads the optical magnifying power and transmits the opticalmagnifying power to the magnifying power conversion section 111. Themagnifying power conversion section 111 converts the optical magnifyingpower into the electron microscope magnifying power corresponding to theoptical magnifying power to display the electron microscope magnifyingpower on the display section 2. The user operates the operation section105B according to the converted magnifying power, and the user setsconditions of the electron beam deflecting and scanning device 58 andthe like such that the electron microscope image is obtained at theconverted magnifying power. Not only the converted magnifying powerconverted by the magnifying power conversion section 111 is alwaysdisplayed on the display section 2, but also display and non-display ofthe converted magnifying power may be switched.

Alternatively, the electron beam scanning and the deflector may be setsuch that the magnifying power conversion section 111 transmits theconverted magnifying power to the electron beam imaging device 11 toautomatically adjust the electron microscope magnifying power. In suchcases, the work that the user manually adjusts the electron microscopemagnifying power adjusting section 68 is eliminated to enhance theconvenience. For example, when the user switches the image displayed onthe display section 2 from the optical image to the electron microscopeimage, the optical magnifying power reading section 112 automaticallyreads the optical magnifying power of the currently-displayed opticalimage, and the magnifying power conversion section 111 converts theoptical magnifying power into the electron microscope magnifying powerof the corresponding electron microscope image. Then, the electronmicroscope image having the electron microscope magnifying power isobtained and automatically displayed on the display section 2. Forexample, the obtained electron microscope image may be scaled togenerate the electron microscope image at the electron microscopemagnifying power, or necessary setting information may be transmitted tothe electron beam imaging device 11 in order to newly obtain theelectron microscope image at the electron microscope magnifying power.Therefore, the electron microscope image having the same size as theoptical image can be displayed on the display section 2. Turn-on andturn-off of the magnifying power automatic cooperative functionperformed by switching between the observation devices may be selected.For example, when the magnifying power automatic cooperative function isturned off, the image is displayed at the magnifying power used in theprevious observation using the electron beam imaging device in switchingthe optical image to the electron microscope image. On the other hand,when the magnifying power automatic cooperative function is turned on,the electron microscope image can be displayed at the automaticallycorresponding magnifying power in switching the optical image to theelectron microscope image.

In the example of FIG. 29, the electron microscope magnifying poweradjusting section 68 is implemented by the operation section 105B.Alternatively, as illustrated in FIG. 2 and the like, the electronmicroscope magnifying power adjusting section 68 may be formed into thering shape so as to be rotatable in the side surface of the optical lensbarrel. The magnifying power adjusting section is also provided in theelectron beam imaging device 11 similarly to the optical magnifyingpower adjusting section 95, so that uniformity of an operational feelingcan be obtained to improve usability.

The magnifying power of the optical zoom lens varies depending on aposition of a lens group that determines the optical magnifying power inthe optical lens system in the optical lens barrel. In order to move thelens group, a zoom ring that is rotatable along the side surface of theoptical lens barrel is provided as the optical magnifying poweradjusting section 95 in the optical lens barrel. The user rotates thezoom ring along the side surface of the optical lens barrel to move theoptical lens in the optical lens barrel, which allows the opticalmagnifying power to be adjusted. Therefore, the magnifying powerdetermined by the rotation position is preferably displayed in the zoomring by the numerical value or the scale such that the rotation positioncan be recognized. For example, an arrow is displayed on the opticalzoom lens side by punching or printing while the magnifying power isdisplayed on the optical lens barrel side by punching or printing, andthe user adjusts the rotation position so as to match the arrow with thedesired magnifying power. As to the dispositions of the arrow and thenumerical value, obviously the optical zoom lens and the optical lensbarrel may be reversed.

In the optical magnifying power adjusting section 95, a mechanismrotated by a motor may be used instead of the manually rotatingoperation of the user. The adjusted magnifying power is detected by theoptical magnifying power reading section 112. When the mechanism thatautomatically adjusts the optical magnifying power adjusting section bythe motor or the like is provided, contrary to the above configuration,the electron microscope magnifying power reading section obtains themagnifying power of the electron microscope image, the magnifying powerconversion section converts the magnifying power of the electronmicroscope image into the magnifying power of the corresponding opticalimage, the information is transmitted to the optical magnifying poweradjusting section such that the converted magnifying power is obtained,and the imaging magnifying power of the optical imaging device isautomatically adjusted.

(Optical Magnifying Power Reading Section 112)

An optical zoom magnifying power reader disposed in the optical lensbarrel can be used as the optical magnifying power reading section 112.The optical magnifying power reading section 112 electrically senses therotation position of a zoom ring 113, thereby recognizing the magnifyingpower. Therefore, for example, the optical zoom lens magnifying powermanually set by the user can be recognized on the magnifying observationapparatus side, and the pieces of processing such as the magnifyingpower conversion can smoothly be performed.

An example of the optical magnifying power reading section 112 isillustrated in a sectional view in FIG. 30. FIG. 30 is a transversesectional view illustrating the optical lens barrel of the opticalimaging device 12, and the zoom ring 113 is rotatably mounted on theouter circumference of the optical lens barrel. A spherical projectionelectrode 114 is elastically projected from the outer circumference ofthe optical lens barrel. A plurality of magnifying power outputelectrodes 115 are provided spaced apart along the circumference on aninner circumference side of the zoom ring 113 in order to output theoptical magnifying power corresponding to the position of the zoom ring113. Each magnifying power output electrode 115 comes into contact withthe projection electrode 114 to output information on the correspondingoptical magnifying power as a voltage signal generated in a resistor,for example. Each magnifying power output electrode 115 is operated asthe switch to detect that the magnifying power corresponding to theposition of the magnifying power output electrode 115 is selected. Thatis, the optical magnifying power reading section 112 recognizes thecurrent optical magnifying power by the turn-on and turn-off of theswitch to transmit the optical magnifying power to the computingportion. A concave surface is formed in the inner surface of the zoomring 113 to receive the projection electrode 114, which allows anexhibition of a positioning function of retaining the zoom ring 113 at aspecific magnifying power. The numerical value or the scale of themagnifying power is displayed in the position of each electrode, whichfacilitates the magnifying power adjusting work of the user. However,when the magnifying power is displayed on the display section 2, it isnot always necessary to physically display the magnifying power.

The optical magnifying power reading section 112 is not limited to theposition detection performed by the electrode contact. For example, aphoto-interrupter may be provided at an interface between the zoom ringand the optical lens barrel to perform the position detection in anon-contact manner. Alternatively, in addition to the discretemagnifying power detection in the fixed position, the magnifying powermay continuously be read using a rotary encoder.

In the example of FIG. 29, the optical imaging device 12 includes theoptical magnifying power adjusting section 95 and the optical magnifyingpower reading section 112. Alternatively, the optical magnifying powerreading section may not be provided. In this case, the user can read thescale displayed on the zoom ring or the like to roughly learn theoptical magnifying power. Alternatively, the optical magnifying poweradjusting section may not be provided, and the fixed magnifying powermay be used. In this case, the optical imaging device is detachablymounted and exchanged to the optical imaging device having the differentmagnifying power, which allows the optical magnifying power to bechanged.

The visual field range may be indicated instead of or in addition to thedisplay of the magnifying power on the display portion 102 in terms ofthe numerical value. For example, the display mode such as not“magnifying power of 100 times” but “display visual field range of 4mm×3 mm” may be used.

(Display of Converted Magnifying Power)

Thus, the magnifying power conversion section 111 recognizes themagnifying power of the image obtained by one of the electron beamimaging device 11 and the optical imaging device 12, and the magnifyingpower conversion section 111 converts the magnifying power into themagnifying power on the basis of the other observation device in orderthat the other observation device obtains an image having thesubstantially same display size as the image.

In the general electron microscope observation, after the visual fieldof the specimen is determined at the low magnifying power using theoptical imaging device 12, the high-magnifying-power image is obtainedby the electron beam imaging device 11. When the optical image obtainedby the optical imaging device 12 is displayed on the display section 2,the optical magnifying power of the optical image is displayed alongwith the converted magnifying power in which the optical magnifyingpower is converted into the electron microscope magnifying power.Therefore, when the user operates the electron beam imaging device 11 toobtain the electron microscope image at the converted magnifying power,the electron microscope image can be obtained at the same display size.As a result, the optical image and the electron microscope image aredisplayed at the same display size on the display section 2 to easilyperform the comparative observation. Particularly, the configuration ofthe specimen chamber 21 (FIG. 17) including the above-described rotarymoving mechanism is also used to easily switch between the opticalimaging device 12 and the electron beam imaging device 11 in the samevisual field, and advantageously the comparative observation is furthereasily performed.

Not only the converted magnifying power in which the optical magnifyingpower is converted into the electron microscope magnifying power, butalso the converted magnifying power in which the electron microscopemagnifying power is converted into the optical magnifying power may beused. Particularly, the converted magnifying power in which the electronmicroscope magnifying power is converted into the optical magnifyingpower is suitably used when the optical image is obtained after theelectron microscope image is obtained. Alternatively, the magnifyingpowers having the different bases are not used, but the magnifyingpowers of the optical image and the electron microscope image may bedisplayed according to the magnifying power unified by one basis.

As described above, not only the converted magnifying power is displayedon the display section 2, but also the magnifying power of theobservation device 10 can automatically be set according to theconverted magnifying power. For example, electron microscope magnifyingpower converted based on the optical magnifying power of the obtainedoptical image may automatically be set to the electron microscopemagnifying power adjusting section 68 of the electron beam imagingdevice 11. Alternatively, an imaging condition parameter isautomatically set such that the image having the electron microscopemagnifying power can be obtained. Therefore, the electron microscopeimage having the same display size as the image obtained by the opticalimaging device 12 can substantially automatically be obtained.Alternatively, the image may not be obtained, and an imaging conditionparameter setting screen may be displayed on the display section 2 sothat the user can finely adjust the imaging condition parameter.

(Automatic Change to Proximity Magnifying Power)

When it is difficult or impossible to obtain the image at the convertedmagnifying power, the magnifying power close to the converted magnifyingpower can be selected to display the magnifying power on the displaysection 2 or to obtain or display the image. That is, because theelectron beam imaging device 11 differs from the optical imaging device12 in the settable magnifying power range, there is a magnifying powerthat can be set in one of the observation devices while being not ableto be set in the other observation device. In such cases, the magnifyingpower as close as possible to the converted magnifying power is selectedfrom the settable range, and the magnifying power can be displayed orthe image can be obtained or displayed.

(Magnifying Power Range Display Section 126)

FIG. 31 is a display example illustrating an overlapping range of theoptical microscope magnifying power range and the electron microscopemagnifying power range in the magnifying power range display section126. When the magnifying power range display section 126 is displayed onthe display section 2, the magnifying power range of each observationdevice can visually be recognized, and how much the image is scaled inwhich direction can be confirmed when the current magnifying power isout of the overlapping range. Particularly, because the electronmicroscope magnifying power range varies according to conditions such asthe acceleration voltage and the working distance, the user can quicklyobtain a necessary index of the magnifying power setting by visuallyrecognizing the overlapping range in the current observation condition.

In this example, the optical microscope magnifying power range and theelectron microscope magnifying power range at least partly overlap eachother in the converted magnifying power, at which the magnifying powerrange of the electron beam imaging device 11 that can be adjusted by theelectron microscope magnifying power adjusting section 68 and themagnifying power range of the optical imaging device 12 that can beadjusted by the optical magnifying power adjusting section 95 areconverted by the magnifying power conversion section 111. Therefore, theelectron microscope image and the optical image can be obtained at thesame size, and advantageously the comparative observation is performed.

In the example of FIG. 31, the optical microscope magnifying power rangeand the electron microscope magnifying power range are displayed in agage type in which they are arrayed on an axis of the convertedmagnifying power of the same basis and overlapped in the one-dimensionalmanner. However, it is not necessary that the overlapping magnifyingpower range be determined only by the value of the observable magnifyingpower of each observation device, but the intended comparativeobservation or the magnifying power range where the synthesis processingcan be performed can be recognized as the overlapping magnifying power.

For example, in synthesizing the images, the images having the same sizeare preferably synthesized. However, there is no limitation to thesynthesis of the images having the same size. For example, assuming thatcolorization is performed by adding color information on the opticalimage to the electron microscope image, when the optical image havingthe same magnifying power as the electron microscope image cannot beobtained by performing the magnifying power conversion, the opticalimage having the closest magnifying power at which the image can beobtained by the optical imaging device 12 can be obtained to obtain thecolor information from the optical image. The observable magnifyingpower of each observation device varies according to the imageobservation condition of each observation device, so that the presenceor absence of the overlapping magnifying power can be recognizedaccording to the variation of the observable magnifying power. Forexample, in the SEM, the observation can be performed at the lowermagnifying power with decreasing acceleration voltage. In the SEM, theobservation can be performed at the lower magnifying power withincreasing working distance that is a distance between the lens and thespecimen.

When the magnifying powers do not overlap each other, the closestmagnifying power inevitably becomes the settable maximum magnifyingpower or the settable minimum magnifying power. However, it is notalways necessary that the closest magnifying power be limited to themaximum or minimum magnifying power, and the similar effect can beobtained at the magnifying power close to the maximum magnifying poweror the minimum magnifying power. Accordingly, in the present invention,the closest magnifying power means not only the magnifying power at onepoint, but also the magnifying power (for example, an error range) thatis substantially equal to the magnifying power at one point.

Because the observable magnifying power of each observation devicevaries according to the image observation conditions of each observationdevice, more preferably, the overlapping of the magnifying power rangesis changed according to the variation of the observable magnifyingpower. For example, in the electron beam imaging device 11, theobservation can be performed at the lower magnifying power withdecreasing acceleration voltage. Further, in the electron beam imagingdevice 11, the observation can be performed at the lower magnifyingpower with increasing working distance between the electron lens and thespecimen. On the other hand, the exchange type optical imaging device 12can be used to change the settable range of the optical magnifyingpower.

When the observation devices are switched under the condition that themagnifying power ranges do not overlap each other, the magnifying powerconversion section 111 computes the closest magnifying power of theother observation device, and the computed magnifying power is set tothe magnifying power of the post-switching. Alternately, the latestmagnifying power used in the observation is stored before theobservation devices are switched, and the magnifying power may be usedas the magnifying power of the post-switching.

(Mode Selecting Section 110)

In the magnifying observation apparatus, the plurality of observationmodes can be selected by the mode selecting section 110. Examples of theobservation mode include the comparative mode and the synthetic mode.When the comparative observation or the synthesis processing isperformed to the electron microscope image obtained by the electron beamimaging device 11 and the optical image obtained by the optical imagingdevice 12, it is desirable that the images obtained by the twoobservation devices 10 have the same observation visual field range. Itis also desirable that the display magnifying powers are brought closeto each other.

(Synthetic Mode)

In the synthetic mode, the synthetic image in which the electronmicroscope image and the optical image are synthesized is generated anddisplayed on the display portion 102. For example, an electronmicroscope image EI illustrated in FIG. 32 and an optical image OIillustrated in FIG. 33 are superimposed to synthesize one syntheticimage data in which information on each pixel is computed as illustratedin FIG. 34. Particularly, luminance information on the electronmicroscope image EI and color information on the optical image OI aresynthesized to generate a color synthetic image GI, thereby obtainingthe high-resolution color image. When a lens aberration such as a strainor a position deviation between the two images exists in the imagesbefore the synthesis, the strain or the position deviation is preferablycorrected before the synthesis processing.

(Image Synthesizing Section 116)

Such image synthesis is performed by an image synthesizing section 116illustrated in FIG. 37, to be described later. The image synthesizingsection 116 synthesizes the color image to display the color image onthe display section 2, whereby a relationship between morphology of thespecimen surface and the color becomes clear to significantly improvethe recognition of the image. When various measurements are performed tothe image displayed on the display section 2, the convenience isimproved by utilizing the color image.

An example of the synthetic image generating method includes a methodfor synthesizing the color information obtained from the optical imageand the luminance information obtained from the electron microscopeimage in each pixel of the coordinate. Alternatively, there may also beadopted a method for extracting image outline information from theelectron microscope image, overlapping the optical image thereon toextract a representative color in the outline from the optical image,and filling the range within the outline with the representative color.In this method, although faithful color reproduction cannotmicroscopically be performed, the synthesis can be performed while thecolor does not overflow from the outline of the observation object, whenthe observation objects are not completely matched with each other dueto an error between the two original images.

The color image can also be synthesized by a method in which the usermanually colors the optical image or the optical image is automaticallycolored based on the electron microscope image that is a grayscaleimage. In such cases, the color information on a region on the opticalimage corresponding to a region that should be colored on the electronmicroscope image is obtained and colored in this color. When the usermanually specifies the color information, for example, the positionincluding the dropper-shaped color on the optical image can be specifiedto obtain the color information.

The existing method and various methods that are developed in the futurecan be used as the image synthesizing technique. For example, asdescribed in Japanese Unexamined Patent Publication No. 10-214583, theelectron microscope image is separated into contrast information imageand brightness information image by the image synthesizing section 116of the controller 1, only the contrast information image is extracted,the color optical image is separated into the contrast information imageand color information image, only the color information image isextracted, and the electron microscope image including the extractedcontrast information image and the optical image including the extractedcolor information image can be synthesized. Alternatively, a methoddescribed in page 153 in the proceedings of 52nd conference of theJapanese Society of Electron Microscopy may be used.

In the image synthesis, the magnifying power of the electron microscopeimage and the magnifying powers of the two (or more) optical images aredesirably set to the same level. At this time, because the maximummagnifying power of the optical imaging device 12 is generally lowerthan the maximum magnifying power of the electron beam imaging device11, the magnifying power range where the synthetic image is obtained isrestricted to the optical magnifying power range. However, the imagesynthesis can be used even if the magnifying powers are not alwaysidentical to each other. For example, the magnifying powers cansubstantially be matched with each other such that the optical image isvirtually enlarged at high magnifying power by the distal zoom or thelike, or such that the electron microscope image is reduced at theoptical image magnifying power. From the viewpoint of adding the colorinformation to the electron microscope image, it is only necessary toprepare the optical image having sharpness to a degree to which thecolor information on the corresponding region can be obtained on theelectron microscope image. Preferably, the sharpness, high-resolutionsynthetic image is advantageously produced when the display sizes arecloser to each other.

The optical image is not limited to the image that is obtained at thesame time as the microscope image, but an image file of the opticalimage that is previously obtained in different timing can be read andused in the coloring processing.

As file formats of the comparative mode and the synthetic mode,general-purpose image file formats such as a bitmap format and JPG cansuitably be used in addition to an optical image file obtained by theoptical imaging device 12, an electron microscope image file obtained bythe electron beam imaging device, and an image file of thepost-synthesis.

(Comparative Mode)

The comparative mode is an observation mode for the comparativeobservation. In the comparative mode, the electron microscope image andthe optical image are simultaneously displayed on the display section 2,or the electron microscope image and the optical image are displayedwhile switched. Therefore, the display portion 102 of the displaysection 2 may be divided into two screens to provide an electronmicroscope image display range 117 and an optical image display range118. FIG. 35 illustrates a display example of the display section 2. InFIG. 35, the display section 2 is horizontally divided into two, and theoptical image is displayed on the left side while the electronmicroscope image is displayed on the right side. The specific magnifyingpower according to each basis is displayed in the upper left of eachimage.

In the present embodiment, the apparatus includes the two observationdevices which are the electron beam imaging device 11 such as the SEMand the optical imaging device 12 such as the digital microscope, andthe magnifying power is defined such that the same visual field rangecan easily be observed by both the observation devices, and such thatthe same magnifying power and the same visual field range are obtainedin both the observation devices. For example, the converted magnifyingpower converted into the magnifying power of one of the observationdevices is displayed on the display section 2 such that the user can setthe magnifying power at which the observation image is obtained orstored by one of the observation devices by using the other observationdevice. Alternatively, the control may be performed such that one of theobservation devices automatically sets the magnifying power of the otherobservation device to the magnifying power of the same basis. Themagnifying power may be unified by not only the matching of themagnifying power of one of the observation devices with the magnifyingpower of the other observation device, but also use of the magnifyingpower that is newly defined by a basis different from the observationdevices.

Next, a flow of action to obtain the images in the same visual fieldrange in the same position at the same tilt angle using the electronbeam imaging device 11 and the optical imaging device 12 will bedescribed. First, in the optical imaging device 12, an observationvisual field range is set by the optical zoom lens. Specifically, theuser adjusts the optical magnifying power by rotating the zoom ring 113that is an optical zoom magnifying power adjusting mechanism mounted onthe optical zoom lens. Then, the optical image is obtained by theoptical imaging device 12.

On the other hand, the rotation position of the zoom ring 113 of theoptical zoom lens is read by the optical magnifying power readingsection 112. The read rotation position is transmitted to the magnifyingpower conversion section 111, whereby the corresponding opticalmagnifying power is computed by the magnifying power conversion section111.

Here, the imaging device is switched from the optical imaging device 12to the electron beam imaging device 11. Specifically, the electron lensbarrel of the electron beam imaging device 11 is moved to the positionof the optical zoom lens barrel of the optical imaging device 12 by therotating device 30. The display switching section 36 is operated toswitch display contents or operating systems if needed.

Then, in an example in which the magnifying observation apparatusinternally recognizes the magnifying power of one of the observationdevices to automatically control the magnifying power of the otherobservation device, the electron microscope magnifying power adjustingsection 68 automatically computes a deflection amount transmitted to theelectron beam deflecting and scanning section controller 55. The samevisual field range as the optical imaging device 12 is automaticallyobserved by the electron lens barrel.

On the other hand, there will be described the case in which the usersets the magnifying power of one of the observation devices by viewingthe magnifying power of the other observation device displayed on thedisplay section 2 when the optical magnifying power reading section isnot included. First, the magnifying power of the optical imaging device12 displayed on the display section 2 is confirmed. Then, the electronmicroscope magnifying power is set by the electron microscope magnifyingpower adjusting section 68 by viewing the displayed magnifying power.The electron microscope magnifying power adjusting section 68 computesthe deflection amount that should be transmitted to the electron beamdeflecting and scanning section controller 55. In this manner, the samevisual field range as the optical imaging device 12 can be observed bythe electron beam imaging device 11.

As described above, the optical image and the electron microscope imagecan be obtained at the same size. In the above example, the electronmicroscope image is obtained after the optical image is obtained. Thisis attributed to the following fact. Although the color image can beobtained by the optical imaging device 12, the maximum magnifying powerof the optical imaging device 12 is generally lower than that of theelectron beam imaging device 11. Therefore, after the observation visualfield is determined at the low magnifying power, the enlarged image isobtained by switching the optical imaging device 12 to the electron beamimaging device 11 having the higher magnifying power. However, there isno limitation to the procedure of using the observation device, and theprocedure of obtaining the optical image after the electron microscopeimage is obtained may also be utilized in the present invention. Anexample of such a procedure will be described below.

The observation visual field range is set by the electron lens barrel.Specifically, the magnifying power is set by the electron microscopemagnifying power adjusting section 68 to obtain the electron microscopeimage. On the other hand, the electron microscope magnifying power ofthe obtained electron microscope image is computed by the electronmicroscope magnifying power reading section.

Then, the observation image is switched from the electron beam imagingdevice 11 to the optical imaging device 12. Specifically, the opticalzoom lens is moved to the position of the electron lens barrel by therotating device 30.

In this case, when the magnifying observation apparatus internallyrecognizes the magnifying power of one of the observation devices toautomatically control the magnifying power of the other observationdevice, the magnifying power conversion section 111 of the controller 1computes the converted magnifying power of the optical image such thatthe same display size is obtained. For example, a rotation signaltransmitted to the optical magnifying power adjusting section 95 iscomputed when the optical imaging device 12 includes the motor-drivenoptical magnifying power reading section 112. Accordingly, the samevisual field range as the electron beam imaging device 11 can beobserved by the optical imaging device 12.

On the other hand, in the example in which the user sets the magnifyingpower of one of the observation devices by viewing the magnifying powerof the other observation device displayed on the display section 2, theelectron microscope magnifying power displayed on the display section 2is confirmed. Then, the magnifying power of the optical zoom lens is setby the zoom ring 113 so as to become the displayed magnifying power. Thesame visual field range as the optical imaging device 12 is observed bythe electron lens barrel.

Only one of the optical magnifying power and the electron microscopemagnifying power, which are displayed on the display section, may bedisplayed or both the magnifying powers may be displayed. The magnifyingpowers may always be displayed, or the magnifying powers may bedisplayed at necessary timings such as the image obtaining and themagnifying power change.

(Real-Time Observation)

The magnifying observation apparatus can switch between the real-timeobservation (also referred to as a live image or moving image) in whichthe image is simply obtained in real time by the observation device tosequentially update the image displayed on the display section 2 and theimaging (also referred to as a still image) in which the high-resolutionimage is obtained in the desired visual field and the obtainedhigh-resolution image is displayed.

In the magnifying observation apparatus, the image is simply obtained inreal time by the observation device to sequentially update the imagedisplayed on the display section 2. In this state, because displaycontents of the display section 2 vary according to the change of thevisual field or the image observation condition, the state isconveniently referred to as moving image display. When the user adjuststhe visual field and the image observation condition to the desiredvalues to obtain the high-resolution image, the obtained high-resolutionimage is displayed on the display section 2. In this state, the displaycontents of the display section 2 become still image display whosedisplay contents are not updated. The moving image display and the stillimage display can appropriately be switched.

(Simple Image)

When the image displayed on the display section is sequentially updatedin the real-time observation; a simple image in which the imaging issimply performed is obtained and displayed in order to shorten a timenecessary to obtain the image. For example, increasing a frame rateduring the imaging can be cited in order to obtain the simple image.Usually 30 seconds to 1 minute per one image is required when theelectron beam imaging device 11 draws the high-resolution image.Additionally, because an S/N ratio is degraded in one image, at least 10images are obtained at the frame rate of about a quarter second perimage during the usual imaging, and the images are averaged anddisplayed. Therefore, at least 2 seconds are required to obtain oneimage. In some cases, at least 30 seconds may be required for the fineobservation image for printing. In the present embodiment, the number ofimages to be averaged is decreased to 8 or 4 images, a restriction isprovided such that an electron beam scanning range is narrowed withrespect to the specimen, or the frame rate is enhanced by processingsuch as decreasing the number of scanning lines, thereby shortening thetime necessary to obtain the image.

(State Display Section 121)

The state display section 121 may be provided on the display section 2in order to distinguish between a moving image display state and a stillimage display state. For example, when the moving image display isswitched to the still image display, the user can visually easilydistinguish between the moving image display state and the still imagedisplay state by the blinking of the magnifying power. As illustrated inFIG. 36, “moving image” and “still image” may be displayed by textdisplay. In this manner, even a beginner user who is unfamiliar with theoperation of the magnifying observation apparatus can distinguishbetween the moving image display state and the still image display statewithout confusion.

Irrespective of the presence or absence of the obtaining of thehigh-resolution image, the image obtained by the currently-selectedobservation device can be set to the moving image display while theimage obtained by the non-selection observation device is set to thestill image display. The image obtained at the time the observationdevice is turned off or switched, namely, the last image obtained by theobservation device is stored in a memory, and the last image can bedisplayed as the image displayed by the still image. This configurationis suitably used when the plurality of observation devices cannotsimultaneously used, or when only the selected observation device can beoperated. Particularly, when the images obtained by the plurality ofobservation devices are simultaneously displayed on one screen, the usercan recognize that the image displayed by the moving image is currentlyselected, and that the image displayed by the still image is currentlynon-selected. For example, in the example of FIG. 35, the optical imageis displayed by the moving image on the left side of the display section2, and the electron microscope image is displayed by the still image onthe right side. Therefore, the user can quickly recognize thecurrently-operable observation device.

Both the images of the optical imaging device and the electron beamimaging device may simultaneously be displayed by the moving image. Insuch cases, when the magnifying power of one of the optical imagingdevice and the electron beam imaging device varies, the magnifying powerof the other imaging device can be changed in conjunction with thevariation of the magnifying power.

(Non-selection Display Section 122)

As to the non-selection observation device, the non-selection displaysection 122 may be provided to indicate that the image displayed on thedisplay section 2 cannot be selected. For example, the image relating tothe non-selection observation device is grayed out on the displaysection 2, the image is displayed by hatching, and an icon or a marksuch as a key is displayed, which allows the user to visually recognizethat the image cannot currently be operated. The lock display isautomatically released by switching the observation device to theselection state. In the mode in which only one of the observationdevices can be operated, the user is notified that the image relating tothe non-selection observation device cannot be operated so as not to beconfused, so that the operability can be improved.

When one of the observation devices is switched to the other observationdevice after the image is obtained by one of the observation devices,the image obtained by the original observation device may continuouslybe displayed as the still image, or the display may be turned off. Inthe present embodiment, the screen of the display section 2 is dividedinto two, and when one of the images is currently observed (movingimage), the other image is displayed by the still image at the time theobservation devices are switched. Therefore, a load such as image dataprocessing can be reduced to efficiently perform the operation byswitching between the observation devices. Obviously, both the imagesmay continuously be displayed as the moving image.

(Converted Magnifying Power Display Section 123)

The magnifying power of the currently-displayed image is displayed onthe display section 2. The real-time magnifying power of the imagedisplayed at this time is displayed in the moving image display, and themagnifying power of the currently-displayed still image is displayed inthe still image display. The magnifying power, which is converted intothe magnifying power when the image is obtained by the observationdevice different from the observation device that obtains the image, canbe displayed as the converted magnifying power display section 123according to the magnifying power determining basis of thecurrently-displayed image. The magnifying power may be convertedaccording to the magnifying power determining basis of the otherobservation device, or the magnifying power may be determined usinganother basis. That is, the image obtained by the different observationdevice is displayed at the unified magnifying power. The convertedmagnifying power display section 123 can display the specific magnifyingpower along with the converted magnifying power. When the convertedmagnifying power cannot be set to one of the observation devices, theconverted magnifying power display section 123 can also display themagnifying power closest to the converted magnifying power in thesettable magnifying powers.

(Predetermined Magnifying Power Display Section 124)

The predetermined magnifying power display section 124 that displays themagnifying power to be applied in the future may be further provided inaddition to the magnifying power display of the currently-displayedimage. For example, in the comparative observation, it is necessary toobtain the images at the same display size by the different observationdevices. Therefore, the target magnifying power is displayed as thepredetermined magnifying power on the display section 2 in order tomanually or automatically obtain the image of one of the observationdevices at the same converted magnifying power as the magnifying powerset to the image of the other observation device. This example will bedescribed with reference to FIG. 36.

In FIG. 36, similarly to FIG. 35, the display section 2 is horizontallydivided into two, the optical image is displayed with the specificmagnifying power by the moving image display in the left optical imagedisplay range 118, and the electron microscope image is displayed withthe specific magnifying power by the still image display in the rightelectron microscope image display range 117. In FIG. 36, thepredetermined magnifying power display section 124 is further added tothe electron microscope image that is the still image. That is, theconverted magnifying power (800 times) same as the magnifying power (800times in FIG. 36) of the optical image displayed by the moving image isdisplayed as a predetermined magnifying power on the predeterminedmagnifying power display section 124 provided on the upper right in theelectron microscope image display range 117. After switching theobservation device 10 from the optical imaging device 12 to the electronbeam imaging device 11, the user sets the imaging condition of theelectron microscope image to perform the imaging such that thispredetermined magnifying power is obtained. Alternatively, the imagingcondition can automatically be set, or the imaging, the display, and thestorage can appropriately be automatized as described below.

(Magnifying Power Determining Section 119)

The magnifying observation apparatus may further include a magnifyingpower determining section 119 that determines whether the opticalimaging device 12 and the electron beam imaging device 11 can be set tothe same converted magnifying power. For example, the magnifying powerdetermining section 119 is implemented in the magnifying powerconversion section 111. In the present embodiment, the MPU constitutingthe magnifying power conversion section 111 also acts as the magnifyingpower determining section 119. For example, when the optical magnifyingpower range that can be adjusted by the optical magnifying poweradjusting section 95 and the electron microscope magnifying power rangethat can be adjusted by the electron microscope magnifying poweradjusting section 68 overlap each other in the converted magnifyingpower, the images can be displayed at the same display size toadvantageously perform the comparative observation. In this case, themagnifying power determining section 119 determines whether theconverted magnifying power of the other observation device can be set tothe magnifying power set to the image currently observed by the movingimage display, and the magnifying power determining section 119 notifiesa determination result to the determination notifying section 125.

(Determination Notifying Section 125)

For example, when the converted magnifying power of the otherobservation device can be set, characters or signs such as “OK” and “◯”are displayed in the display range of the other observation device, aframe of the predetermined magnifying power display section 124 isdisplayed by a bold line as illustrated in FIG. 36, a double frame,highlighting, and blinking display are used in a singular or combinedmanner, the magnifying power is displayed in blue in the display rangedisplayed by the moving image, or a background of the magnifying powercan be colored in blue. Therefore, because the user can easily recognizethat the images can be observed at the same display size, after theobservation devices are switched, the setting work can be advanced suchthat the observation can be performed at the magnifying power.

The determination notifying section 125 may further include a warningfunction of displaying that the magnifying power of one of theobservation devices cannot be set to the converted magnifying power,when the magnifying power of one of the observation devices cannot beset to the converted magnifying power that becomes the same display sizeduring the observation of the other observation device. Specifically,when the determination results of the magnifying power determiningsection 119 shows that the magnifying power cannot be set, the convertedmagnifying power display section 123 is displayed in red in the displayrange in one of the observation devices, characters or signs such as“×”, “−”, and “Magnifying power cannot be set” are displayed, a warningsound is emitted, the display range is displayed by the gray out orhatching, or the display range is made unselectable. In this manner, theuser can recognize that the observation cannot be performed at thedisplay size, even if the magnifying power is out of the overlappingrange of the optical microscope magnifying power range and the electronmicroscope magnifying power range in changing the magnifying power.Therefore, the user can take action to change the magnifying power toanother magnifying power such that the settable determination result isobtained. As described above, in the determination notifying section125, various decoration methods that can be distinguished from otherdisplays can appropriately be used according to the determination resultof the magnifying power determining section 119. More preferably, thedetermination notifying section 125 and the gage-shaped magnifying powerrange display section 126 of FIG. 31 are simultaneously used, so thatthe user can visually recognize where the current magnifying power islocated with respect to the overlapping range.

(Guide Section 120)

A guide section 120 may be further included to encourage the user tochange the magnifying power to the settable magnifying power when theother observation device cannot be set to the converted magnifyingpower. For example, by using message display or audio guidance, theguide section 120 encourages the user to perform the magnifying powerchanging operation such that the magnifying power is changed to themagnifying power that can be set to both the observation devices. Guidecontents may include an operation necessary to set the magnifying powerand an instruction of the parameter setting in addition to the simpledisplay of the magnifying power. Particularly, the method is effectivelyused for a beginner user who is unfamiliar with the operation of themagnifying power setting.

When the magnifying power determining section 119 determines that themagnifying power cannot be set, the magnifying power that is closest tothe converted magnifying power in the settable magnifying powers can bedisplayed on the converted magnifying power display section 123. In suchcases, the converted magnifying power display section 123 directlydisplays the converted magnifying power when it is determined that themagnifying power can be set, and the converted magnifying power displaysection 123 displays the settable magnifying power closest to theconverted magnifying power when it is determined that the magnifyingpower cannot be set. Not only the magnifying power is simply displayed,but also the magnifying power adjusting section of the observationdevice may be sent to the converted magnifying power displayed on theconverted magnifying power display section 123 or the image mayautomatically be obtained and stored. For example, the magnifying poweris set at the timing in which the observation devices are switched as atrigger. The user-friendly magnifying observation apparatus in whichlaborsaving of the user setting work is achieved during the comparativeobservation or the image synthesis can be implemented by the automation.

In the above example, the converted magnifying power display sectiondisplays the converted magnifying power on the display section.Alternatively, the turn-on and turn-off, namely, the display state andthe non-display state can be switched during the display of theconverted magnifying power. Even if the converted magnifying power isnot displayed, the display magnifying power can automatically bedisplayed as the settable, closest magnifying power.

The magnifying power that is applied in switching the observationdevices or the magnifying power that should be applied is alwaysdisplayed on the predetermined magnifying power display section 124. Inthe example of FIG. 36, the predetermined magnifying power displaysection 124 is provided only in the display range that is displayed bythe still image. However, the present invention is not limited thereto,and the predetermined magnifying power display section may be providedin the display range that is displayed by the moving image. In suchcases, the same magnifying power as the converted magnifying powerdisplay section is displayed on the predetermined magnifying powerdisplay section.

Preferably, the basis of the previously used observation device is usedas the magnifying power basis. Generally, as described above, the targetis fixed from the wide visual field range using the optical image, andthe fine information is obtained using the electron microscope image.Therefore, the magnifying powers are displayed in a unified manner bymatching the magnifying power basis with the basis of the optical image,which allows the user to obtain the images at the same display size onthe unified magnifying power display without confusion. Obviously, theobservation device basis specified by the user or another basis can beused.

(Timing at which Determination Notifying Section 125 Issues Warning)

The determination notifying section 125 always issues the warning orconfirmation during the observation, namely, the determination notifyingsection 125 quickly issues the warning or confirmation at the time themagnifying power of the image is out of the overlapping range.Alternatively, the determination notifying section 125 may issue thewarning or confirmation at necessary timing.

For example, not only the determination notifying section 125immediately performs the notification when the magnifying power is outof the overlapping range as a result of the change in magnifying powerduring the observation, but also the determination notifying section 125may issue the warning as a sign of confirmation only in an importantstage such as when obtaining or storing the image. The determinationnotifying section 125 may issue the notification at timings such as whenthe observation devices are switched, or when the magnifying power isset by the magnifying power adjusting section. The determinationnotifying section 125 may issue the notification not only at one of thetimings but also at a plurality of timings.

(Warning Contents of Determination Notifying Section 125)

For example, the determination notifying section 125 notifies the userthat the observation cannot be performed at the same convertedmagnifying power by the other observation device because the magnifyingpower is out of the overlapping range, or the determination notifyingsection 125 displays a dialogue that encourages the user to determinewhether the processing is continued or stopped although the currentmagnifying power is out of the overlapping magnifying power.Alternatively, although the currently-set magnifying power is out of theoverlapping range, the determination notifying section 125 may display adialogue that encourages the user to select (A) the magnifying powerwhen switched to the other observation device is set to the closestmagnifying power in the settable magnifying powers, (B) the magnifyingpower set in the previous observation is used, or (C) the processing isstopped. Alternatively, although the currently-set magnifying power isout of the overlapping range, the determination notifying section 125may display a dialogue that causes the user to select (A) the magnifyingpower when switched to the other observation device is set to theclosest magnifying power in the settable magnifying powers or (B) theprocessing is stopped. Further, although the currently-set magnifyingpower is out of the overlapping range, the determination notifyingsection 125 may also display a dialogue that causes the user to confirmand select (A) the magnifying power when switched to the otherobservation device is set to the previous observation magnifying poweror (B) the processing is stopped.

Examples of the warning issuing method include a method for encouragingthe user to perform the confirmation and selection by displaying adialogue screen on a magnifying observation apparatus operating programthat is installed in the computer of FIG. 18 and displayed on thedisplay section 2 and operated, and a method for performing thenotification by displaying a message in a dedicated message region orcomment region that is previously provided as the determinationnotifying section 125 on the program displayed on the display section 2.

When the currently-observed magnifying power falls within theoverlapping range as a result of the change in magnifying powerperformed by the user according to the above notification, thedetermination notifying section 125 can notify the user that thecurrently-observed magnifying power falls within the overlapping range.For example, the determination notifying section 125 quickly providesthe notification when the magnifying power is switched from the outsideof the overlapping range to the inside of the overlapping range. Asdescribed above, the determination notifying section 125 may provide thenotification at the timings when one of the images is obtained or storedand when the observation devices are switched. As to the notificationmethod, for example, a format of the converted magnifying power displaysection 123 is changed when the magnifying power falls within theoverlapping range. Specifically, the display color or the backgroundcolor of the magnifying power is changed from red to blue, or thehatching or the gray out is released. Alternatively, a selectionprohibition state and the gray out of an imaging button and a storagebutton are released on the program to return to an active state in whichthe selection or pressing operation can be performed. Alternatively, amessage that the imaging can be performed at the same magnifying powerin the overlapping range is displayed by a dialogue or the dedicatedcomment region. In this manner, the user is notified at the necessarytiming by the determination notifying section 125 that the imaging canbe performed at the same display size, so that the user can obtain anoperation environment in which the user can quickly recognizeavailability of the comparative observation.

As described above, the magnifying observation apparatus includes thespecimen chamber whose internal space can be decompressed; the electronbeam imaging device as the first observation device for obtaining theelectron microscope image in the specimen chamber; the electronmicroscope magnifying power adjusting section that adjusts the electronmicroscope magnifying power of the electron microscope image obtained bythe electron beam imaging device; the optical imaging device as thesecond observation device for being able to obtain the optical image inthe specimen chamber; the optical magnifying power adjusting sectionthat adjusts the optical magnifying power, the optical magnifying powerbeing a magnifying power of the optical image obtained by the opticalimaging device, the optical magnifying power being determined on thebasis different from that of the electron microscope magnifying power;the display section that displays the electron microscope image obtainedby the electron beam imaging device and the optical image obtained bythe optical imaging device while switching between the electronmicroscope image and the optical image, or simultaneously displays theelectron microscope image and the optical image; the mode selectingsection 110 that can select the comparative mode and the synthetic modeas the observation mode, the comparative observation of the electronmicroscope image and the optical image being able to be performed in thecomparative mode, the synthetic image in which the electron microscopeimage and the optical image are synthesized being able to be displayedin the synthetic mode; and the magnifying power conversion section 111that recognizes the magnifying power of the image obtained by one of theelectron beam imaging device and the optical imaging device and convertsthe magnifying power, which is used to obtain the image having thedisplay size substantially identical to that of the image, by the otherobservation device into the magnifying power on the basis of the otherobservation device. In the comparative mode or the synthetic mode, theimage obtained by one of the electron beam imaging device and theoptical imaging device is displayed on the display section, and themagnifying power is converted by the magnifying power conversion section111 in order to obtain the image at the substantially same size as theimage with the other observation device, and the converted magnifyingpower can be displayed on the display section or the magnifying powerclosest to the converted magnifying power in the settable magnifyingpowers can be displayed on the display section when the convertedmagnifying power cannot be set. Therefore, the magnifying power isdisplayed in the unified manner irrespective of the observation deviceto be used, so that the images can easily be obtained at the samedisplay size during the comparative observation in which the imageshaving the same display size are compared and the synthetic mode inwhich the synthetic image is obtained by synthesizing the images.

Preferably, in the comparative mode, the magnifying power of theelectron microscope image is matched with the magnifying power of theoptical image. Therefore, the magnifying power conversion sectionconverts the magnifying power of the image obtained by one of theelectron beam imaging device and the optical imaging device into themagnifying power obtained by the other observation device. However, inthe comparative observation, it is not necessary to completely match themagnifying powers or visual fields with each other, but the userappropriately performs the selection according to the observationapplication or purpose. Similarly, in the synthetic mode, it is notalways necessary to completely match the magnifying powers of theelectron microscope image and the optical image, but the image can besynthesized even at the different magnifying powers. Particularly, whenthe electron microscope image has the high magnifying power while theoptical image has the low magnifying power, the luminance information orthe outline information on the electron microscope image having thenarrow visual field and the color information on the correspondingregion is extracted from the optical image having the wide visual fieldare synthesized by enlargement or projection. The synthesized image canpractically be used without any difficulty although the colorinformation slightly blurs. Even if the image quality is slightlydegraded due to the mismatch of the magnifying power between thesynthesized images, the images can be synthesized at a level at whichthe synthetic image can be used without any difficulty. Therefore, themagnifying power determining section can make not only the determinationas to whether the optical imaging device can be set to the convertedmagnifying power that is converted by the magnifying power conversionsection and corresponds to the magnifying power of the electronmicroscope image, but also the determination as to whether the opticalimaging device can be set to the magnifying power that is located in aspecific synthesizable range on the basis of the converted magnifyingpower. In this case, the magnifying power in the specific synthesizablerange depends on accuracy of the determined synthetic image. Forexample, the synthetic image is practically obtained without anydifficulty when a magnifying power difference is 20 times or less.Contrarily, the optical image having the high magnifying power and theelectron microscope image having the low magnifying power can besynthesized in principle. However, in such cases, because the quality ofthe synthetic image is degraded, as described above, the image synthesisof the images whose magnifying powers are not matched with each other ispreferably applied when the magnifying power of the electron microscopeimage is higher than that of the optical image.

(Measuring Function)

The magnifying observation apparatus further includes a measuringfunction of being able to measure a distance between specified twopoints or an area within a specified region on the image displayed onthe display section 2. In the measuring function, any of the electronmicroscope image, the optical image, and the synthetic image isdisplayed on the display section 2, and any point on the image isspecified by a pointing device such as a mouse, thereby performing themeasurement. In order to specify the point, there can be suitably usednot only the position specified by the user is directly used as themeasuring point, but also a snap function of detecting edge informationclose to the pointed position is detected from the image to use the edgeposition as the measuring point.

Although any image can be used in the measuring function, the electronmicroscope image or the synthetic image is preferably used. The opticalimage has the color information and the luminance information in eachpixel, but a boundary line of the color information and a boundary lineof the luminance information tend to become unclear. Particularly, inthe measurement at the high magnifying power, the resolution tends to beinsufficient in the optical image, the outline or the edge of thespecimen that is the measuring target blurs, and particularly thecorrect measuring point is hardly specified during the measurement whenthe snap function is used. On the other hand, the electron microscopeimage has the luminance information in each pixel but does not have thecolor information. At the same time, the boundary line of the luminanceinformation is clear, and the edge of the structure can relativelyclearly be observed even at the high magnifying power. However, theelectron microscope image is not naturally viewed with the colorinformation, but is a monochrome contrast image depending on electrongeneration efficiency of the specimen, which results in a problem inthat the measurement object is difficult to be intuitively recognized.Therefore, the high-resolution synthetic image having the colorinformation is most easily used.

For example, the color information on the optical image and theluminance information on the electron microscope image are synthesizedin the synthetic image. However, because the two original images ofpre-synthesis have the specific coordinate systems, reference positionsand reference lengths of FIG. 33 of the images are not exactly matchedwith one another. Even if correction is performed by some kind ofmethod, an error is not completely eliminated. Therefore, the twooriginal images do not correctly become the same magnifying power andthe same observation position, but some errors are included in both themagnifying power and the observation position. When the measurement isperformed using the synthetic image, unfortunately measurement accuracyis degraded due to the errors of the coordinate position and themagnifying power. For example, when the distance between the two pointsis measured, because the error is generated in specifying the positions,the error is accumulated in the measurement in which the two points arespecified.

On the other hand, in the present embodiment, the measurement isperformed using positional information on the electron microscope imagethat is the original image when the measurement is performed from thesynthetic image. That is, the boundary line of the measurement objectcan correctly be specified by removing the errors, such as thepositional information on the optical image that is the original image,the magnifying power generated in the image synthesis, and the erroraccumulation of the observation position, which are caused by thesynthesis.

FIG. 37 is a block diagram illustrating the magnifying observationapparatus including the measuring function in the synthetic image. Themagnifying observation apparatus of FIG. 37 includes the electron beamimaging device 11 that obtains the electron microscope image, theoptical imaging device 12 that obtains the optical image, an operationsection 105C, the controller 1, and the display section 2.

The operation section 105C acts as the electron microscope magnifyingpower adjusting section 68 that sets the display magnifying power of theelectron microscope image, the optical magnifying power adjustingsection 95 that sets the display the magnifying power of the opticalimage, and a measuring point specification section 130 that specifiesthe measuring point on the screen of the display section with respect tothe synthetic image displayed on the display section.

The controller 1 includes the first storage section 131 that retains theelectron microscope image, the second storage section 132 that retainsthe optical image, a third storage section 133 in which the positionalinformation on the synthetic image is stored, the display switchingsection 36 that switches the image displays, the image synthesizingsection 116, the magnifying power conversion section 111, the modeselecting section 110, the magnifying power determining section 119, theguide section 120, and a measuring section 134. The display switchingsection 36 switches the image display on the display section 2 from thedisplay of the optical imaging device 12 to the display of the electronbeam imaging device 11. The controller 1 includes the computer, the CPU,or the LSI. However, each function may be implemented by an individualmember. For example, the observation condition setting section or theoptical magnifying power reading section can be separated from theoperation section. As described above, the display section acts as theconverted magnifying power display section 123, the magnifying powerrange display section 126, the predetermined magnifying power displaysection 124, the determination notifying section 125, and the statedisplay section 121.

The operation section 105C acts as an observation condition settingsection that sets the image observation condition of the electron beamimaging device 11. The user operates the observation condition settingsection to set the image observation condition when the electronmicroscope image is obtained by the electron beam imaging device 11.Examples of the image observation conditions include the accelerationvoltage, a spot size (diameter of incident electron beam flux), a typeof the detector, a vacuum level for the electron microscope. The imageobservation conditions are set by the observation condition settingsection according to the electron beam imaging device 11 to be used. Theimage observation conditions set by the observation condition settingsection are transmitted to the electron beam imaging device through thecontroller 1. Similarly, imaging conditions of the optical imagingdevice are set. The controller 1 obtains the electron microscope imagefrom the electron beam imaging device 11 and the optical image from theoptical imaging device 12, and stores the electron microscope image inthe first storage section 131 and the optical image in the secondstorage section 132, respectively. When the synthetic mode is selectedby the mode selecting section 110, the image synthesizing section 116synthesizes the positional information on the electron microscope imageand the color information on the optical image to generate the syntheticimage based on the pieces of information stored in the first storagesection 131 and the second storage section 132, and the synthetic imageis displayed on the display section. The third storage section 133retains correspondence information indicating a correspondencerelationship between the positional information on the synthetic imageor the positional information on the synthetic image and the positionalinformation on the electron microscope image of the pre-synthesis.

In this state, in order to perform the measurement based on thesynthetic image, the user first operates the measuring pointspecification section 130 to specify the measuring point on the screenwith respect to the synthetic image displayed on the display section.Then the measuring section 134 performs the specified measurement.Examples of the measurements include the distance between the twopoints, a height difference, the tilt angle, and computation of the areaof the specified closed region. Here, the positional information on theelectron microscope image that becomes the origin of the synthetic imageis used in performing the measurement. Therefore, the positionalinformation on the electron microscope image is previously stored in thefirst storage section 131 in retaining the electron microscope image.The positional information indicates the structure of the specimen thatis the observation target, and the positional information is thecoordinate position or the outline of the shape. By the use of thepositional information, the correct position corresponding to themeasuring point specified on the image can be obtained.

When the shape of the synthetic image is correctly matched with that ofthe original electron microscope image, the positional information onthe synthetic image can directly be used in the measurement. On theother hand, when the shape of the synthetic image is not correctlymatched with that of the original electron microscope image, thecoordinate position on the electron microscope image corresponding tothe coordinate position on the synthetic image is obtained by referringto the third storage section 133, and the measurement is performed usingthe electron microscope image coordinate. Therefore, even if themisalignment of the shape or the coordinate position is generated by theimage synthesis of the optical image and the electron microscope image,the measurement can be performed with high accuracy by converting thecoordinate position into the coordinate position on the electronmicroscope image having the more accurate coordinate positioninformation.

(Operation Section 105C)

Both the optical imaging device 12 and the electron beam imaging device11 are controlled by the common operation section 105C, and pieces ofinformation necessary to measure the images obtained by both theobservation devices, for example, the magnifying power and a positionalrelationship between the specimen and the optical axis of theobservation device are collectively processed by the control section.Therefore, the convenience can significantly be improved in the colorsynthetic image measuring work. For example, the common operationsection 105C may also function as the external controller 1, and theoptical imaging device 12 and the electron beam imaging device 11 can beoperated by one controller 1 while switched. Preferably, the opticalimaging device 12 and the electron beam imaging device 11 can beoperated by magnifying observation apparatus operating program installedin the computer while switched. Additionally, as described above, theobservation devices are switched by rotating type, so that theobservation devices can easily be switched and moved such that the sameposition of the specimen is observed. Therefore, advantageously thecolor synthetic image synthesizing work is further simply performed.

In the configuration of FIG. 17 or 38, the body portion 24 is rotated toobserve the same visual field from the same direction (tilt angle).Examples of the method for recognizing that one of the observationdevices is located in the position where the other observation devicehas been originally located include a method for electrically learningthe rotation angle by disposing a rotating position detecting section264 such as a rotary encoder in the body portion and a method forvisually learning the rotation angle by providing a scale or a mark inthe body portion and the fixed side.

In the above example, the specimen chamber includes the rotating typemoving mechanism as illustrated in FIGS. 17 and 38. However, the presentinvention is not limited to the above configuration, and variousconfigurations in which one specimen chamber includes a plurality ofobservation devices can be used. FIGS. 39 to 42 illustrate modificationsof the configuration of the specimen chamber 21 including the opticalimaging device 12 and the electron beam imaging device 11. In eachexample, the optical imaging device 12 and the electron beam imagingdevice 11 are disposed so as to be able to image the same specimen SA.

In the example of FIG. 39, the observation devices 10 are switched by arotating revolver. In the example of FIG. 40, the observation devices 10are switched by translation. In the configurations of FIGS. 39 and 40,the side of the observation device 10 is moved while the specimen stage33 is fixed. However, the present invention is not limited thereto, andthe side of the observation device 10 may be moved. For example, FIG. 41illustrates a configuration in which the specimen stage 33 istranslated, and FIG. 42 illustrates a configuration in which thespecimen stage 33 is tilted. In the example of FIG. 43, the optical axesof the observation devices 10 are selected by a half mirror. Asdescribed above, the present embodiment can appropriately be used invarious modes including the plurality of observation devices 10.

In the example of FIG. 43, the optical axes of the optical imagingdevice 12 and the electron beam imaging device 11 are coaxiallydisposed. In FIG. 41, the optical axes of the optical imaging device 12and the electron beam imaging device 11 are disposed in parallel. InFIG. 42, the optical axes of the optical imaging device 12 and theelectron beam imaging device 11 are disposed into a V-shape.Particularly, in the configuration of FIG. 43, the optical axis of theoptical imaging device 12 and the optical axis of the electron beamimaging device 11 are disposed so as to be matched with each other, sothat preferably the images can be obtained in the same visual field.Additionally, in this configuration, it is not necessary to move thespecimen stage 33 in switching between the image signal of the opticalimaging device 12 and the image signal of the electron beam imagingdevice 11, so that the switching can quickly be performed. Additionally,the real-time observation and the moving image observation can also beimplemented. Additionally, because the optical imaging device 12 isdisposed in the specimen chamber 21 to maintain the decompression stateor the vacuum state in the specimen chamber 21, the decompressionprocess can be eliminated to implement the smooth switching when thedisplay switching section 36 switches between the imaging systems. Thesmooth switching between the imaging systems implements the seamlessdisplay switching, and the user-friendly electron microscope can beimplemented. However, in the configuration of FIG. 43, because theoptical axes of the optical imaging device 12 and the electron beamimaging device 11 are coaxially disposed, it is necessary to dispose amirror to fold the optical axis of the optical imaging device 12 on theoptical axis of the electron beam imaging device 11, which results in aproblem in that the configuration becomes complicated to increase cost.Moreover, the complicated apparatus having the coaxial configurationdecreases a degree of freedom in the optical design of the opticalimaging device 12 and the electron beam imaging device 11, and possiblyimage performance is influenced.

On the other hand, the mirror is eliminated in the configurations ofFIGS. 40 to 42, and the configurations can be implemented at relativelylow cost. However, in the configuration of FIG. 41, it is necessary totranslate the specimen stage 33 during the switching, or it is necessaryto dispose the optical imaging device 12. Therefore, in addition to thetroublesome work, it is necessary to perform the adjustments such as thepositioning, thereby disturbing the real-time observation. When theoptical imaging device 12 is disposed in the atmosphere, it is necessaryto evacuate the specimen chamber 21 in which the electron beam imagingdevice 11 is disposed. Therefore, a large amount of time and effort isinvolved. On the other hand, in the configuration of FIG. 42, becauseone of the optical axes is tilted, it is necessary to tilt the specimenstage 33 from the horizontal plane in order to obtain the same visualfield. In such cases, it is necessary to perform the adjustments such asthe positioning, thereby disturbing the real-time observation. Asdescribed above, in the configurations of FIGS. 41 and 42, it isdifficult to switch between the optical imaging device 12 and theelectron beam imaging device 11 in real time. In order to solve thisproblem, after the optical image is previously obtained as the data bythe optical imaging device 12, the specimen SA is moved to the positionwhere the specimen SA can be observed by the electron beam imagingdevice 11, and the electron microscope image is set to the displayablestate. In this state, when the optical image is displayed on the displaysection 2 to search the visual field, the display switching section 36quickly switches the optical imaging device 12 to the electron beamimaging device 11, so that the optical image can be switched to theelectron microscope image in real time without changing the hardwareconfiguration. Therefore, a memory portion in which the optical imageobtained by the optical imaging device 12 is stored is used in thisconfiguration. A semiconductor memory such as a RAM can be used as thememory portion.

(Configuration Example in which Two Heads are Mounted on One Controller)

In the above example, the plurality of observation devices are providedin the same specimen chamber 21 or specimen stage 33. However, thepresent embodiment can be applied to the magnifying observationapparatus that observes the different specimens. For example, in theexample of FIG. 44, an optical microscope 11B and an electron microscope12B, which are separately provided, are controlled by a commoncontroller 1B. Therefore, the magnifying power displays of the opticalimage and the electron microscope image, which are displayed on thedisplay section, can be converted into the unified magnifying power anddisplayed on the side of the controller 1B, the magnifying power of oneof the images can be converted into the converted magnifying power andset to the other observation device, and when the converted magnifyingpower cannot be set, the converted magnifying power can be set to themagnifying power closest to the converted magnifying power in thesettable magnifying powers. In such cases, the two different specimens,namely, a specimen SA4 placed on a specimen stage 33D of the electronmicroscope 12B and a specimen SA5 placed on a specimen stage 33E of theoptical microscope 11B are observed. In the above examples, the twoimaging devices, namely, the optical imaging device and the electronbeam imaging device are used as the observation device. Alternatively,at least three observation devices may be provided while freelyswitched.

The magnifying observation apparatus of the present invention cansuitably be applied to the function of performing scaling display of theobtained observation image in an electron beam appearance inspectionapparatus, an electron beam length measuring apparatus, a particle beaminspection apparatus, and the like, which are used in a process ofevaluating and measuring a characteristic of a semiconductor elementwith the electron beam or the ion beam that are the charged particle. Inaddition to the SEM, the magnifying observation apparatus of the presentinvention can be applied as the lens of the electron beam imaging device11 to a TEM, Scanning Probe Microscopes (SPM) such as a ScanningTunneling Microscope (STM) and an Atomic Force microscope (AFM), a lasermicroscope, and an X-ray microscope.

What is claimed is:
 1. A magnifying observation apparatus comprising: aspecimen chamber being able to decompress as an internal space; anelectron beam imaging device as a first observation device for obtainingan electron microscope image in the specimen chamber, and wherein saidelectron beam imaging device has an adjustable electron magnifying powerrange; an electron microscope magnifying power adjusting section thatadjusts an electron microscope magnifying power of the electronmicroscope image obtained by the electron beam imaging device; anoptical imaging device as a second observation device for obtaining anoptical image in the specimen chamber, and wherein said optical imagingdevice has an adjustable optical magnifying power range, and saidadjustable electron magnifying power range has an overlapping range withsaid adjustable optical power range; an optical magnifying poweradjusting section that adjusts an optical magnifying power, the opticalmagnifying power being a magnifying power of the optical image obtainedby the optical imaging device, the optical magnifying power beingdetermined on a basis different from that of the electron microscopemagnifying power; a moving device that moves each of the observationdevices such that an optical axis direction of one of the observationdevices is substantially aligned with an optical axis direction of theother observation device; a display section that displays the electronmicroscope image obtained by the electron beam imaging device and theoptical image obtained by the optical imaging device while switchingbetween the electron microscope image and the optical image, orsimultaneously displays the electron microscope image and the opticalimage; and a magnifying power conversion section that recognizes themagnifying power of a first image obtained by the optical imaging devicewithin the overlapping range and converts the magnifying power into aconverted magnifying power, on a basis of the electron beam imagingdevice, which is used by the electron beam imaging device, to obtain asecond image having a display size that is substantially identical tothat of the first image; and wherein the electron microscope magnifyingpower adjusting section adjusts the electron microscope magnifying powerto the converted magnifying power from the magnifying power conversionsection.
 2. The magnifying observation apparatus according to claim 1,wherein a converted magnifying power in which the electron microscopemagnifying power or optical magnifying power of the image obtained byone of the observation devices and displayed on the display section isconverted into the electron microscope magnifying power or opticalmagnifying power of the other observation device by the magnifying powerconversion section is displayed on the display section, or a magnifyingpower that is set close to the converted magnifying power is displayedon the display section when the converted magnifying power is not set bythe other observation device.
 3. The magnifying observation apparatusaccording to claim 1, wherein the converted magnifying power in whichthe electron microscope magnifying power or optical magnifying power ofthe image obtained by one of the observation devices is converted intothe electron microscope magnifying power or optical magnifying power ofthe other observation device by the magnifying power conversion sectionis automatically set by the magnifying power adjusting section of theother observation device, or a magnifying power that is set close to theconverted magnifying power is automatically set by the magnifying poweradjusting section of the other observation device when the convertedmagnifying power is not set by the other observation device.
 4. Themagnifying observation apparatus according to claim 1, furthercomprising an image synthesizing section that synthesizes the electronmicroscope image obtained by the electron beam imaging device and theoptical image obtained by the optical imaging device.
 5. The magnifyingobservation apparatus according to claim 1, wherein the optical imagingdevice includes: a zoom mechanism that magnifies the optical image; anda magnifying power recognizing section that recognizes a magnifyingpower magnified by the zoom mechanism, and the electron microscopemagnifying power adjusting section includes: a parameter setting sectionthat sets a parameter relating to the magnifying power of the electronmicroscope image obtained by the electron beam imaging device; and anelectron microscope magnifying power computing section that recognizesthe parameter set by the parameter setting section and computes theelectron microscope magnifying power obtained by the parameter.
 6. Themagnifying observation apparatus according to claim 1, wherein thedisplay section is configured to simultaneously display the electronmicroscope image and the optical image at an identical magnifying powerin terms of the converted magnifying power on the basis of one of themagnifying powers.
 7. The magnifying observation apparatus according toclaim 1, wherein the apparatus is configured to operate in a comparativemode and a synthetic mode, and wherein comparative observation of theelectron microscope image and the optical image is performed in thecomparative mode, and wherein a synthetic image in which the electronmicroscope image and the optical image are synthesized is displayed inthe synthetic mode.
 8. The magnifying observation apparatus according toclaim 1, further comprising a magnifying power range display sectionthat one-dimensionally displays an electron microscope magnifying powerrange and an optical magnifying power range on the display section whileconverting the electron microscope magnifying power range and theoptical magnifying power range into a magnifying power on an identicalbasis, the electron microscope magnifying power range being obtained bythe electron beam imaging device, the optical magnifying power rangebeing obtained by the optical imaging device.
 9. The magnifyingobservation apparatus according to claim 1, wherein the convertedmagnifying power, that is used by the electron beam imaging device toobtain the second image having the display size that is substantiallyidentical to that of the first image, is a magnifying power that is notset by the electron beam imaging device, and the magnifying powerconversion section outputs as the converted magnifying power amagnifying power that is closest to the converted magnifying power andwhich is selected from the magnifying powers that are set by theelectron beam imaging device.
 10. The magnifying observation apparatusaccording to claim 1, wherein the moving device is a rotating devicethat rotates the electron beam imaging device and the optical imagingdevice along a cylindrical shaped outer surface of the body portion suchthat a distance to a common rotation axis is kept constant while opticalaxes of the electron beam imaging device and the optical imaging deviceare maintained in a posture oriented toward the common rotation axis.11. The magnifying observation apparatus according to claim 1, whereinthe specimen stage includes a horizontal surface moving mechanism thatmoves the specimen stage in a horizontal plane while the specimen stageis maintained in a non-tilted state in a horizontal posture and a heightadjusting mechanism that adjusts the height of the specimen stage. 12.The magnifying observation apparatus according to claim 11, wherein theheight adjusting mechanism comprises a rotating device configured torotate about an axis of rotation.
 13. The magnifying observationapparatus according to claim 1, wherein the magnifying power is definedby a value in which an identical display range is divided by theobservation visual field range.
 14. The magnifying observation apparatusaccording to claim 1, wherein the optical imaging device includes anoptical magnifying power reading section that reads the set magnifyingpower.
 15. The magnifying observation apparatus according to claim 14,wherein the optical magnifying power reading section is configured toread the magnifying power of the optical image, the magnifying powerconversion section is configured to convert the magnifying power of theelectron microscope image corresponding to the read optical magnifyingpower, and the display section is configured to display the electronmicroscope image of the converted magnifying power.
 16. The magnifyingobservation apparatus according to claim 1, wherein the convertedmagnifying power converted by the magnifying power conversion section isconfigured to switch between a state in which the converted magnifyingpower is displayed on the display section and a state in which theconverted magnifying power is not displayed.
 17. The magnifyingobservation apparatus according to claim 16, wherein a controller thatcontrols the electron beam imaging device also controls the opticalimaging device.
 18. A magnifying observation apparatus comprising: aspecimen chamber being able to decompress as an internal space; a firstspecimen stage on which a first specimen of an observation target isplaced; an electron beam imaging device as a first observation devicefor obtaining an electron microscope image in the specimen chamber, andwherein said electron beam imaging device has an adjustable electronmagnifying power range; an electron microscope magnifying poweradjusting section that adjusts an electron microscope magnifying powerof the electron microscope image obtained by the electron beam imagingdevice; a second specimen stage on which a second specimen of anobservation target is placed; an optical imaging device as a secondobservation device for obtaining an optical image of the secondspecimen, and wherein said optical imaging device has an adjustableoptical magnifying power range, and said adjustable electron magnifyingpower range has an overlapping range with said adjustable optical powerrange; an optical magnifying power adjusting section that adjusts anoptical magnifying power, the optical magnifying power being amagnifying power of the optical image obtained by the optical imagingdevice, the optical magnifying power being determined on a basisdifferent from that of the electron microscope magnifying power; adisplay section that displays the electron microscope image of the firstspecimen obtained by the electron beam imaging device and the opticalimage of the second specimen obtained by the optical imaging devicewhile switching between the electron microscope image and the opticalimage, or simultaneously displays the electron microscope image and theoptical image; and a magnifying power conversion section that recognizesa magnifying power of a first image obtained by the optical imagingdevice within the overlapping range and converts the magnifying powerinto a converted magnifying power, on a basis of the electron beamimaging device, which is used by the electron beam imaging device, toobtain a second image having a magnifying power that is substantiallyidentical to that of the first image; and wherein the electronmicroscope magnifying power adjusting section adjusts the electronmicroscope magnifying power to the converted magnifying power from themagnifying power conversion section.